1. A hydrocarbon is a molecule made of hydrogen atoms where the carbon serves as the backbone.
3. Petroleum is a very valuable resource because one can either burn it or use it to make new substances. Most importantly, petroleum makes plastic. It is also cheap and easy to refine.
5. Oil is crude because it is not renewable and it takes a long time to naturally form. It is very valuable and we depend on it so much, that if we ran out, it would be a world disaster.
6.
a) The average number of barrels of petroleum used daily in the United States for building purposes is 4,000,000 barrels
b) 16,000,000 barrels of petroleum are burned as fuel daily in the United States.
7. Gasoline and diesel fuel come from crude petroleum.
8.
a) plastic hangers, pantyhose, flip flops, fake fur
b) We could use wooden hangers to hang our clothes, wear cotton pantyhose, wear flip flops made of cloth, and wear real fur or fleece.
10.
a) The Middle East
b) Western Europe
11.
a) North America, Central Asian, Eastern Europe, Western Europe, the Far East, and Oceania.
b) Africa, Central and South America, and the Middle East.
12. Density can be used to separate different liquids with the process of distillation.
13. Acetone and water would be the easiest to separate from each other because acetone has a much lower boiling point, and therefore would evaporate very quickly leaving pure water behind.
15. Check paper
16. Fractional distillation is different from simple distillation because fractional distillation separates the substance into many different sections and creates different physical states not only liquid.
17.
light: aviation gas and motor gas, naphthas and solvents, petrochemicals, kerosene, and refined oils
intermediate: gas oil, petrochemicals, heavy furnace oil, and diesel fuel oil
heavy distillates: lubricating oil and grease, heavy oils and wax, cracking stock, and petrochemicals
residues: lubricating oil and fuel oil, petroleum jelly, road oils and asphalt, and petroleum coke.
18. The bottom fraction would have the highest boiling point because it is a solid.
19. You could further separate the fractions by redoing the process of distillation according to the properties of the substances in the mixture.
20. Methane, pentane, hexane, and octane. The more hydrogen that a molecule contains, the higher the boiling point.
21. A covalent bond is a bond between atoms where valence electrons are shared.
22. Atoms with filled outer electron shells do not form covalent bonds with other atoms because they are nonreactive since there shells are completed and they have no reason to attach to other atoms.
23. Each atom needs the shared electron in order to be stable, and therefore they both equally have it. This relates how the dogs both want the sock because it makes both of them happy. The bond is not broken until there is a chemical reaction, which would be one of the dogs taking away the sock and sharing it with another dog.
26.
a) A structural formula has the shape of a three dimensional molecule while a molecular formular just represents the atoms
b) A structural formula is inadequate of an actual molecule because it does not show it in 3D. A real atom is 3-dimensional.
27. Check paper
28. It only shows four dots because carbon has four valence electrons. The four electrons are the electrons that are available in the outer shell for sharing.
29.
a) C9H20
b) C16H34
c) C10H22
d) C18H38
30.
a) 128g
b) 226g
c) 142g
d)254g
31.
a) Heptane, C7H16
b) ??
32. It implies that the carbon-carbon bonding is a single covalent bond
33. Yes, the models are isomers of one another because they have the same chemical formula but have different branches and layouts.
34. Check paper
35. The shortest-chain alkane that demonstrates isomerism is CH4
36. Both representations are correct because the formation of the hydrocarbon molecules does not have to be identical each time. The formation can be different but the structure of the individual molecule must remain the same.
37. Check paper
38.
a) A short straight chain because it is easier to separate.
b) A short branched chain because it would be denser and smaller and easier to separate
c) A short branched chain because it has less molecules and therefore the bonds are not as strong.
Wednesday, July 20, 2011
What I got out of summer Chem
What I found most valuable in Dr. Forman's chemistry class was the study of water pollution and water shortage. The debate opened my eyes up to a lot of different viewpoints on water as well. As Katrina and I were the only people in the class who thought water pollution was a bigger issue, we were able to share our opinions and reasons for believing that with other people as we also got to hear why water shortage is a big conflict as well. I also learned a lot about water from not only the video, but from our first lab, the water filtration lab. There are a lot of processes that need to take place in order for water to become drinkable and its very expensive to do all those procedures to a very large quantity of water that is enough for a region or country. Summer school has been a good experience because I have become aware of which ways I learn best. I don't think summer school is the right program for me because It takes time for me to process ideas and understand them. Reviewing is necessary for my understanding of a topic and with such a rushed class, that is not as much time available to review certain topics over and over again.
Tuesday, July 19, 2011
p. 258, #1-10
1. Petroleum is sometimes called "buried sunshine" because the energy stored in petroleum originally came from the sun.
2.
a. potential energy: energy of position (ex. a ball on top of a steep hill)
b. kinetic energy: energy related to motion (ex. a child riding a bike)
3. During a chemical reaction, existing bonds are broken and new bonds are formed.
4. A molecule of butane has more potential energy because it has more carbons, which means that the molecule has more electrons.
5.
a) potential energy
b) potential energy
c) kinetic energy
d) potential energy
e) potential energy
6. Energy is required to break chemical bonds because it is needed to break preexisting bonds and reorganize to form new bonds. The products have less potential energy than they did before the chemical reaction took place.
7.
a) exothermic reaction
b) endothermic reaction
c) exothermic reaction
8. Burning of a candle gives off heat energy, therefore it is an exothermic reaction. The product has less energy than the original reactants because it has to give off its energy in order for the reaction to create fire.
9. See picture
10. The law of conservation of energy states that energy can not be created nor destroyed in any chemical, mechanical, or physical processes.
2.
a. potential energy: energy of position (ex. a ball on top of a steep hill)
b. kinetic energy: energy related to motion (ex. a child riding a bike)
3. During a chemical reaction, existing bonds are broken and new bonds are formed.
4. A molecule of butane has more potential energy because it has more carbons, which means that the molecule has more electrons.
5.
a) potential energy
b) potential energy
c) kinetic energy
d) potential energy
e) potential energy
6. Energy is required to break chemical bonds because it is needed to break preexisting bonds and reorganize to form new bonds. The products have less potential energy than they did before the chemical reaction took place.
7.
a) exothermic reaction
b) endothermic reaction
c) exothermic reaction
8. Burning of a candle gives off heat energy, therefore it is an exothermic reaction. The product has less energy than the original reactants because it has to give off its energy in order for the reaction to create fire.
9. See picture
10. The law of conservation of energy states that energy can not be created nor destroyed in any chemical, mechanical, or physical processes.
p. 360, #14-20
14. CO2 and water vapor maintain the stable surface temperature of the Earth. When the sun rays hit the eEarth, gas molecules absorb most of the radiation, preventing the high levels of heat from reaching the Earth. During the nighttime, the heat that has been absorbed by the gasses is released, and this helps the temperature stay warm enough.
15.
a)
natural processes: the carbon cycle
human activities: CO2 released from cars
b)
natural processes: A cow's digestion which releases methane into the air
16.
a) increase: a high amount of CO2 levels in the air, trapping the heat on Earth
b) decrease: An increase of gas molecules because fewer rays would reach the surface
17. A greenhouse with transparent glass walls is much warmer than a structure with opaque wooden walls because the radiation waves that enter the greenhouse do not escape easily because they keep reflecting off of the glass back onto the ground.
18.
a)
b)
19. Methane, carbon dioxide, and limestone.
20. Carbon atoms go through the carbon cycle, which takes the carbon atoms through the atmosphere, biosphere, lithosphere, and hydrosphere. It enters the atmosphere when carbon is released as carbon dioxide. It enters the hydrosphere when it is used in plants for respiration and is in glucose form. It becomes part of the biosphere when the CO2 is exhaled from plants becoming oxygen, that is inhaled by humans and exhaled as CO2 by humans. CO2 is also inhaled by underwater plants which also makes it part of the hydrosphere. It is also formed into limestone which makes it part of the lithosphere.
15.
a)
natural processes: the carbon cycle
human activities: CO2 released from cars
b)
natural processes: A cow's digestion which releases methane into the air
human activities: Burning of methane
16.
a) increase: a high amount of CO2 levels in the air, trapping the heat on Earth
b) decrease: An increase of gas molecules because fewer rays would reach the surface
17. A greenhouse with transparent glass walls is much warmer than a structure with opaque wooden walls because the radiation waves that enter the greenhouse do not escape easily because they keep reflecting off of the glass back onto the ground.
18.
a)
19. Methane, carbon dioxide, and limestone.
20. Carbon atoms go through the carbon cycle, which takes the carbon atoms through the atmosphere, biosphere, lithosphere, and hydrosphere. It enters the atmosphere when carbon is released as carbon dioxide. It enters the hydrosphere when it is used in plants for respiration and is in glucose form. It becomes part of the biosphere when the CO2 is exhaled from plants becoming oxygen, that is inhaled by humans and exhaled as CO2 by humans. CO2 is also inhaled by underwater plants which also makes it part of the hydrosphere. It is also formed into limestone which makes it part of the lithosphere.
p. 344, #1-4
1. Human exposure to ultraviolet radiation is more dangerous than exposure to infrared radiation because infrared radiation is the least energetic. UV lights can cause sunburn, skin cancer, and are even hot enough to be used for sterilization. Infrared radiation is mostly just heat energy and is not very harmful.
2. Visible solar radiation energizes electrons and provides energy in order for photosynthesis reactions to occur.
3. There is less water vapor in dry areas like New Mexico and Arizona, and therefore infrared radiation is not stored and reradiated back into the atmosphere but is just stuck at the surface of the Earth. That is what is causing dry hot weather during the day and cold temperatures at night. However in places such as Florida, there is an abundant amount of water vapor in the air which absorbs the heat, keeping the temperature more stable.
4.
a. If the Earth had fewer gas molecules the days would be much hotter because there would not be enough molecules to absorb the heat and reflect it back to the atmosphere, and therefore, the heat would be stuck on the surface.
b. A less dense atmosphere would make the nights much cooler because there would not be enough gas molecules to absorb the heat and maintain it for the night.
2. Visible solar radiation energizes electrons and provides energy in order for photosynthesis reactions to occur.
3. There is less water vapor in dry areas like New Mexico and Arizona, and therefore infrared radiation is not stored and reradiated back into the atmosphere but is just stuck at the surface of the Earth. That is what is causing dry hot weather during the day and cold temperatures at night. However in places such as Florida, there is an abundant amount of water vapor in the air which absorbs the heat, keeping the temperature more stable.
4.
a. If the Earth had fewer gas molecules the days would be much hotter because there would not be enough molecules to absorb the heat and reflect it back to the atmosphere, and therefore, the heat would be stuck on the surface.
b. A less dense atmosphere would make the nights much cooler because there would not be enough gas molecules to absorb the heat and maintain it for the night.
Monday, July 18, 2011
p. 361, #1-8
1. The frequency of electromagnetic radiation and its energy is directly proportional. Therefore, the higher the energy, the higher the frequency.
2. Spectrum is a good descriptor of the types of energy found in electromagnetic radiation because the spectrum shows the range of energy from the lowest types to the highest.
3. Visible light is useful in plant photosynthesis because it energizes electrons in some chemical bonds. Infrared radiation does not have enough energy and ultraviolet light is too powerful and would damage the plants.
4.
a. Infrared radiation, visible light, and ultraviolet radiation.
b. Infrared radiation is heat energy and affects the temperatures of nonliving and living things on Earth. Visible radiation has a big influence on plant photosynthesis, giving the plants the power they need. Ultraviolet radiation gives us the essential vitamin D we need but can also cause sunburn and skin cancer.
5. Visible light does not have enough energy to to sterilize lab goggles. On the other hand, UV-C (ultraviolet light used to sterilize) can break covalent bonds and kill bacteria and germs in order to sterilize objects.
6. Infrared radiation mostly absorbed my carbon dioxide and water and does not reach Earth's surface. 90% of visible radiation reaches the Earth and causes red sunsets and blue skies. Ultraviolet radiation is mostly absorbed by the atmosphere and only a small amount reaches Earth's surface, however this is a good thing because if not then most likely everything on Earth would be destroyed.
7. When solar radiation is trapped by greenhouse gasses, it can cause an increase in temperature on Earth's surface. It can also increase the amount of water vapor which then enters the atmosphere.
8.
a. A lake will heat up more quickly. Water stores and absorbs heat while asphalt also reflects the energy back into space.
b. Water has a higher specific heat capacity than asphalt.
2. Spectrum is a good descriptor of the types of energy found in electromagnetic radiation because the spectrum shows the range of energy from the lowest types to the highest.
3. Visible light is useful in plant photosynthesis because it energizes electrons in some chemical bonds. Infrared radiation does not have enough energy and ultraviolet light is too powerful and would damage the plants.
4.
a. Infrared radiation, visible light, and ultraviolet radiation.
b. Infrared radiation is heat energy and affects the temperatures of nonliving and living things on Earth. Visible radiation has a big influence on plant photosynthesis, giving the plants the power they need. Ultraviolet radiation gives us the essential vitamin D we need but can also cause sunburn and skin cancer.
5. Visible light does not have enough energy to to sterilize lab goggles. On the other hand, UV-C (ultraviolet light used to sterilize) can break covalent bonds and kill bacteria and germs in order to sterilize objects.
6. Infrared radiation mostly absorbed my carbon dioxide and water and does not reach Earth's surface. 90% of visible radiation reaches the Earth and causes red sunsets and blue skies. Ultraviolet radiation is mostly absorbed by the atmosphere and only a small amount reaches Earth's surface, however this is a good thing because if not then most likely everything on Earth would be destroyed.
7. When solar radiation is trapped by greenhouse gasses, it can cause an increase in temperature on Earth's surface. It can also increase the amount of water vapor which then enters the atmosphere.
8.
a. A lake will heat up more quickly. Water stores and absorbs heat while asphalt also reflects the energy back into space.
b. Water has a higher specific heat capacity than asphalt.
Sunday, July 17, 2011
p. 204, #7-13
7. An alloy is a solid solution consisting of atoms of two or more metals.
8. Two common alloys are brass and steel. Brass is made from copper and zinc. We use brass in plumbing, screws, and lighting fixtures. Steel is made from iron and carbon. Steel is used in car and plane parts, kitchen utensils, kitchen appliances, and commonly in modern house architecture.
9. Carbon is used in stainless steel and in steel.
10. AlMg- magnalium (magnesium and aluminum). It is strong and used in airplane bodies and ladders.
11. Semiconductors are between the metals and nonmetals on the periodic table.
12. Boron, arsenic, and phosphorous are commonly used for doping semiconductors.
13. They are commonly used in electronic devices such as transistors and integrated circuits for computers.
8. Two common alloys are brass and steel. Brass is made from copper and zinc. We use brass in plumbing, screws, and lighting fixtures. Steel is made from iron and carbon. Steel is used in car and plane parts, kitchen utensils, kitchen appliances, and commonly in modern house architecture.
9. Carbon is used in stainless steel and in steel.
10. AlMg- magnalium (magnesium and aluminum). It is strong and used in airplane bodies and ladders.
11. Semiconductors are between the metals and nonmetals on the periodic table.
12. Boron, arsenic, and phosphorous are commonly used for doping semiconductors.
13. They are commonly used in electronic devices such as transistors and integrated circuits for computers.
p. 204, #1-6
1. Allotropes are different forms of an element that each have distinctly different physical or chemical properties but are in the same state.
2. Oxygen and silicon form allotropes.
3.
a. Diamond is a very hard substance, it is not a good conductor, it is colorless, and is very valuable and expensive. Coal is a cheap, powdery substance that is used for fuel. Graphite is another cheap substance that is black, a good conductor, and extremely soft.
b. Their properties are different because they are carbon allotropes and have varied atomic assortments and different structures.
c. Something is either expensive or cheap depending on it's usefulness, appearance, and quality.
4. Engineered materials are materials that were created by a scientist to have specific characteristics of interest through manufacturing methods while natural materials are uncontrolled and untouched by scientists.
5. Ceramics work well under high temperatures and have very high melting points, however they are brittle and can crack during rapid changes in temperature.
6. Creating plastic can create a lot of pollution, therefore finding a way to create plastic without polluting the air would be a very positive change. In addition, plastic melts very easily when in contact with high temperatures. If the melting point was higher, plastic would be much more useful.
2. Oxygen and silicon form allotropes.
3.
a. Diamond is a very hard substance, it is not a good conductor, it is colorless, and is very valuable and expensive. Coal is a cheap, powdery substance that is used for fuel. Graphite is another cheap substance that is black, a good conductor, and extremely soft.
b. Their properties are different because they are carbon allotropes and have varied atomic assortments and different structures.
c. Something is either expensive or cheap depending on it's usefulness, appearance, and quality.
4. Engineered materials are materials that were created by a scientist to have specific characteristics of interest through manufacturing methods while natural materials are uncontrolled and untouched by scientists.
5. Ceramics work well under high temperatures and have very high melting points, however they are brittle and can crack during rapid changes in temperature.
6. Creating plastic can create a lot of pollution, therefore finding a way to create plastic without polluting the air would be a very positive change. In addition, plastic melts very easily when in contact with high temperatures. If the melting point was higher, plastic would be much more useful.
p. 182, #18-21
18.
a. Reusing is using the same item many times for the same or a different purpose than the item was initially made for. Recycling is to reprocess an item into a different item.
b. Two examples of reusing are using tote bags for grocery store shopping instead of plastic bags, and using metal water bottles instead of plastic water bottles. Two examples of recycling are recycling glass bottles, cans, paper, and plastic bottles into their proper disposal containers.
19. renewable resources: fertile soil, plants, animals, and fresh water.
nonrenewable resources: natural gas, coal, metals, and petroleum.
20.
a. Reusing
b. Recycling
c. Reusing
21. A light bulb is produced from plastics, chemicals, and glass. A newspaper is produced from plants and chemicals. One can throw a newspaper away in a trashcan, but light bulbs must be thrown away carefully because there are many chemicals inside. (ex. mercury).
a. Reusing is using the same item many times for the same or a different purpose than the item was initially made for. Recycling is to reprocess an item into a different item.
b. Two examples of reusing are using tote bags for grocery store shopping instead of plastic bags, and using metal water bottles instead of plastic water bottles. Two examples of recycling are recycling glass bottles, cans, paper, and plastic bottles into their proper disposal containers.
19. renewable resources: fertile soil, plants, animals, and fresh water.
nonrenewable resources: natural gas, coal, metals, and petroleum.
20.
a. Reusing
b. Recycling
c. Reusing
21. A light bulb is produced from plastics, chemicals, and glass. A newspaper is produced from plants and chemicals. One can throw a newspaper away in a trashcan, but light bulbs must be thrown away carefully because there are many chemicals inside. (ex. mercury).
Wednesday, July 13, 2011
p. 181, #13-17
13.
a. 6 moles of NH3 are needed to react with 9 mol PbO
b. 5 moles of N2 are produced by the reaction of 10 mol NH3
c. 5 moles of Pb are produced from 5 mol PbO
14.
a. 17 moles of N2 can be produced from 34g of NH3
b. 621g of Pb can be produced from the complete reaction of 3.0 mol PbO
**c. 17g of N2 can be produced from 34.0 g NH3
d. 415 g of PbO will produce 415 g Pb
15. It is not 67% because two oxygen atoms are 32g and a carbon atom is 12g. You would do the equation 32/32 + 12 x 100% which equals 73%.
16.
a. 87% silver
b. 53% aluminum
c. 40% calcium
17.
a. 68% lead
b. 50% PbSO4
c.10% lead
d. see paper
a. 6 moles of NH3 are needed to react with 9 mol PbO
b. 5 moles of N2 are produced by the reaction of 10 mol NH3
c. 5 moles of Pb are produced from 5 mol PbO
14.
a. 17 moles of N2 can be produced from 34g of NH3
b. 621g of Pb can be produced from the complete reaction of 3.0 mol PbO
**c. 17g of N2 can be produced from 34.0 g NH3
d. 415 g of PbO will produce 415 g Pb
15. It is not 67% because two oxygen atoms are 32g and a carbon atom is 12g. You would do the equation 32/32 + 12 x 100% which equals 73%.
16.
a. 87% silver
b. 53% aluminum
c. 40% calcium
17.
a. 68% lead
b. 50% PbSO4
c.10% lead
d. see paper
Tuesday, July 12, 2011
p. 180, #1-12
1. The law of conservation of matter is the statement that matter can neither be destroyed nor created.
2. A scientific law summarizes what has been learned my observation of nature.
3. These expressions are misleading because according to the law of conservation of matter, matter can not be disposed of by "throwing it away" and can not disappear by being "used up". Molecules can only be changed and decomposed, however this does not apply to atoms. Atoms are indestructible.
4.
a. Unbalanced
b. Unbalanced
c. Balanced
5.
a. 3
b. 2
c. 1
6. See paper
a. 1, 3, 1, 3
b. 2, 3, 2, 2
c. 2, 3, 2
7.
a. 1, 3, 2, 2
b. 2, 25, 16, 18
8.
a. Yes.
b. No. Instead of changing the coefficients when balancing the equation, he changed the subscripts.
c. 1 Na2SO4 + 2KCL --> 2 NaCl + 1 K2SO4
9. It would take 400,000 seconds
10.
a. 32g
b. 48g
c. 100g
d. 58g
e.180g
11. Although copper and sodium have different masses, volumes, and densities, they have the same weight of each atom per mol.
12.
a. one atom
b. .5 atoms
c. .1 atoms
d. .03 atoms
2. A scientific law summarizes what has been learned my observation of nature.
3. These expressions are misleading because according to the law of conservation of matter, matter can not be disposed of by "throwing it away" and can not disappear by being "used up". Molecules can only be changed and decomposed, however this does not apply to atoms. Atoms are indestructible.
4.
a. Unbalanced
b. Unbalanced
c. Balanced
5.
a. 3
b. 2
c. 1
6. See paper
a. 1, 3, 1, 3
b. 2, 3, 2, 2
c. 2, 3, 2
7.
a. 1, 3, 2, 2
b. 2, 25, 16, 18
8.
a. Yes.
b. No. Instead of changing the coefficients when balancing the equation, he changed the subscripts.
c. 1 Na2SO4 + 2KCL --> 2 NaCl + 1 K2SO4
9. It would take 400,000 seconds
10.
a. 32g
b. 48g
c. 100g
d. 58g
e.180g
11. Although copper and sodium have different masses, volumes, and densities, they have the same weight of each atom per mol.
12.
a. one atom
b. .5 atoms
c. .1 atoms
d. .03 atoms
Metal report: Zinc
Zinc
My metal report is on Zinc (Zn), the 24th most abundant element on Earth's crust. Before I get into details about this element, I am going to state the basic facts first. Zn has 30 protons and 30 electrons. It has 35 neutrons, resulting in a total atomic mass of 65.39. It is the first element in group 12 of the periodic table. The only ion found in zinc is Zn2+. It's melting point is 419.53 degrees celsius and its boiling point is 907 degrees celsius. Zinc is naturally solid, most abundantly found in China, Canada, Japan, Australia, and the Republic of Korea. It is found as a bluish white, lustrous metal and has a hexagonal crystal structure. It is a fair conductor of electricity and is quite reactive. It has the lowest melting point of all the transition metals aside from mercury and cadmium. Zinc is usually hard and brittle but it becomes rather malleable when between the temperatures of 100 and 150 degrees celsius. It has five stable isotopes. Zn-65 is the longest lasting isotope (243.8 days), while Zn-62 is the shortest lasting (9.26 hours).
Problems with Zinc
While Zinc is an essential element, intaking too much or too little zinc can cause problems. We need zinc in our body for proper taste and smell, the proper healing of wounds, and healthy skin. Listed are the problems that can occur if someone has zinc deficiency. These problems are more prominent in third world countries:
My metal report is on Zinc (Zn), the 24th most abundant element on Earth's crust. Before I get into details about this element, I am going to state the basic facts first. Zn has 30 protons and 30 electrons. It has 35 neutrons, resulting in a total atomic mass of 65.39. It is the first element in group 12 of the periodic table. The only ion found in zinc is Zn2+. It's melting point is 419.53 degrees celsius and its boiling point is 907 degrees celsius. Zinc is naturally solid, most abundantly found in China, Canada, Japan, Australia, and the Republic of Korea. It is found as a bluish white, lustrous metal and has a hexagonal crystal structure. It is a fair conductor of electricity and is quite reactive. It has the lowest melting point of all the transition metals aside from mercury and cadmium. Zinc is usually hard and brittle but it becomes rather malleable when between the temperatures of 100 and 150 degrees celsius. It has five stable isotopes. Zn-65 is the longest lasting isotope (243.8 days), while Zn-62 is the shortest lasting (9.26 hours).
While Zinc is an essential element, intaking too much or too little zinc can cause problems. We need zinc in our body for proper taste and smell, the proper healing of wounds, and healthy skin. Listed are the problems that can occur if someone has zinc deficiency. These problems are more prominent in third world countries:
- Growth retardation
- Delayed sexual maturation
- Infection
- Diarrhea
Listed are the problems that can occur with consumption of excess zinc:
- Ataxia (loss of full control of body movements)
- Lethargy (lack of energy, sleeplessness)
- Copper deficiency
Ways to obtain one's essential dosage of Zinc is to eat the following foods:
- Oysters
- Beans
- Nuts
- Almonds
- Pumpkin seeds
- Sunflower seeds
- Whole grains
- Veal liver
- Low fat roast beef
- Dark chocolate and cocoa powder
- Lamb
Founding of zinc
Zinc was discovered in 1746 by scientist Andreas Marggraf. The name zinc comes from the German word zin, which means tin. It is used as a metal coating, a rust protectant, in brass, in bronze, and in nickel.
Reactivity
Zinc is a strong reducing agent, meaning it is used to add electrons to other metals. When zinc is burned in the air, it forms a bright bluish-green flame and gives off fumes of zinc oxide. Zinc reacts with acids, alkali metals, and non-metals. When bonded with another element, it creates covalent bonds.
Reactivity
Zinc is a strong reducing agent, meaning it is used to add electrons to other metals. When zinc is burned in the air, it forms a bright bluish-green flame and gives off fumes of zinc oxide. Zinc reacts with acids, alkali metals, and non-metals. When bonded with another element, it creates covalent bonds.
Uses
Zinc is used to form numerous alloys. Alloys are metals that are mixed together to make an alternate metal. These alloys include brass, bronze, nickel silver, soft solder, German silver, spring brass, and aluminum solder. It is also used to make die castings for use in the electrical, automotive, and hardware industries. Die casting is a process that forces molten metal under high pressure into a mold cavity. Zinc oxide is used in paints, rubbers, cosmetics, plastics, inks, soap, batteries, pharmaceuticals etc...…
Sources
http://chemistry.about.com/od/elementfacts/a/zinc.htm
http://www.chemicalelements.com/elements/zn.html
http://en.wikipedia.org/wiki/Zinc#Dietary_intake
Monday, July 11, 2011
p. 151, #9-22
9. Active metals are more difficult to process and refine because they are constantly reacting with the substances around them, making it harder to separate them from their compounds.
10. The metals that would be the easiest to process would be copper and silver because they are the least reactive.
11. Most metals exist in nature as minerals because most metals are reactive.
12. Calcium will most likely react with chromium(III) because it is more reactive than chromium. More reactive substances react with less reactive substances.
13. The first reaction is more likely to occur because the more reactive element is causing the ions of the less reactive element to change to a metal.
14.
a. It would be a bad idea because iron is more reactive than lead, resulting in the decomposition of the spoon.
b. Pb2+(aq) + Fe(s) à Pb+(aq) + Fe+(s)
15. During reduction, a reactant gains electrons and during oxidation, a reactant loses electrons.
16.
a. Ag3+ + 3e- à Ag
b. Và V4+ + 4e-
c. Cu+ à Cu2+ + e-
17.
a. reduction
b. oxidation
c. reduction
18.
a. Zinc has been oxidized because it has lost electrons.
b. Nickel has been reduced because it has gained electrons.
c. Zinc is the reducing agent
19.
a. Potassium has been oxidized because it has lost an electron.
b. Mercury has been reduced because it gained electrons
c. The oxidizing agent is mercury
20.
a. Al(s) + Cr3+(aq) à Al3+(aq) + Cr(s)
b. Mn2+(aq) + Mg(s) à Mn(s) + Mg2+(aq)
21.
a. Electrometallurgy uses an electric current to add electrons to ions, thus reducing the ion into an atom.
b. Pyrometallurgy uses thermal heat to supply electrons to the ion. Carbon and carbon monoxide serve as the reducing agents.
c. Hydrometallurgy treats ores and other metal containing materials with reactants in a water solution.
22.
a. Electrometallurgy
b. Pyrometallurgy
10. The metals that would be the easiest to process would be copper and silver because they are the least reactive.
11. Most metals exist in nature as minerals because most metals are reactive.
12. Calcium will most likely react with chromium(III) because it is more reactive than chromium. More reactive substances react with less reactive substances.
13. The first reaction is more likely to occur because the more reactive element is causing the ions of the less reactive element to change to a metal.
14.
a. It would be a bad idea because iron is more reactive than lead, resulting in the decomposition of the spoon.
b. Pb2+(aq) + Fe(s) à Pb+(aq) + Fe+(s)
15. During reduction, a reactant gains electrons and during oxidation, a reactant loses electrons.
16.
a. Ag3+ + 3e- à Ag
b. Và V4+ + 4e-
c. Cu+ à Cu2+ + e-
17.
a. reduction
b. oxidation
c. reduction
18.
a. Zinc has been oxidized because it has lost electrons.
b. Nickel has been reduced because it has gained electrons.
c. Zinc is the reducing agent
19.
a. Potassium has been oxidized because it has lost an electron.
b. Mercury has been reduced because it gained electrons
c. The oxidizing agent is mercury
20.
a. Al(s) + Cr3+(aq) à Al3+(aq) + Cr(s)
b. Mn2+(aq) + Mg(s) à Mn(s) + Mg2+(aq)
21.
a. Electrometallurgy uses an electric current to add electrons to ions, thus reducing the ion into an atom.
b. Pyrometallurgy uses thermal heat to supply electrons to the ion. Carbon and carbon monoxide serve as the reducing agents.
c. Hydrometallurgy treats ores and other metal containing materials with reactants in a water solution.
22.
a. Electrometallurgy
b. Pyrometallurgy
Thursday, July 7, 2011
p. 151, #1-8
1.
Lithosphere: Coal and oil
Atmosphere: H20 and Co2
Hydrosphere: H20 and 3.5% of NaCl
2 a .
The crust: the surface of the earth that we live on
The mantle: molten rock that creates hot spots and is a source for volcanos
The core: the magnetic center of the earth, very hot
b. The lithosphere contains the most chemical resources used in manufacturing.
3.
a. silver: Mexico
b. copper: Japan
c. tin: China
4. China produces the most
5. Minerals are different from ores because minerals are a pure form and are not attached to other substances. An ore is a mineral that is attached to other substances, yet the mineral can still be detached from the other substances.
6. Factors that determine the feasibility of mining a particular metallic ore at a site is whether the spot has traces of the ore found or if the site has colors in the rock that are the same colors of the mineral that is being targeted.
7. Factors that may have influenced the decision to reopen the mine are that more of the gold may have formed and now be visibly minable.
8. A "useful ore" means that the mineral has at least 1% of of mineral crystals inside of it.
4.
5.
6.
7.
8.
Lithosphere: Coal and oil
Atmosphere: H20 and Co2
Hydrosphere: H20 and 3.5% of NaCl
2 a .
The crust: the surface of the earth that we live on
The mantle: molten rock that creates hot spots and is a source for volcanos
The core: the magnetic center of the earth, very hot
b. The lithosphere contains the most chemical resources used in manufacturing.
3.
a. silver: Mexico
b. copper: Japan
c. tin: China
4. China produces the most
5. Minerals are different from ores because minerals are a pure form and are not attached to other substances. An ore is a mineral that is attached to other substances, yet the mineral can still be detached from the other substances.
6. Factors that determine the feasibility of mining a particular metallic ore at a site is whether the spot has traces of the ore found or if the site has colors in the rock that are the same colors of the mineral that is being targeted.
7. Factors that may have influenced the decision to reopen the mine are that more of the gold may have formed and now be visibly minable.
8. A "useful ore" means that the mineral has at least 1% of of mineral crystals inside of it.
4.
5.
6.
7.
8.
p. 132, #26-28, 29-34
26. Metallic elements are more likely to lose electrons.
27. It indicates that they are very nonreactive.
28.
a. Na: cation
b. Ca: cation
c. F: anion
d. Cu: cation
e. O: anion
f. Li: cation
g. Sn: cation
h. I: anion
29. B. oxygen with mass number 16 and oxygen with mass number 18. The only difference between the two is that one is an isotope and the other isn't, however they are still chemically exactly the same. Copper metal and copper(II) are very different. One is very active while the other is not.
30. The diameter of a calcium ion is 205 pm
31. a. change in color: a fence being painted (physical), iron rusting (chemical)
b. change in temperature: sidewalk in the sun (physical), exothermic reaction from two elements reacting together (chemical)
c. formation of a gas: water boiling (physical), HCl and zinc reacting giving off hydrogen gas bubbles (chemical)
32.
a: Bromine
b: Silicon
33. The date from the fish kill mystery was based off of unusual levels of certain elements that occurred in an extreme pattern. The periodic table is like the chart of the fish kill date because it is also sorted out in a pattern.
34. Thorium and protactinium and uranium and neptunium.
27. It indicates that they are very nonreactive.
28.
a. Na: cation
b. Ca: cation
c. F: anion
d. Cu: cation
e. O: anion
f. Li: cation
g. Sn: cation
h. I: anion
29. B. oxygen with mass number 16 and oxygen with mass number 18. The only difference between the two is that one is an isotope and the other isn't, however they are still chemically exactly the same. Copper metal and copper(II) are very different. One is very active while the other is not.
30. The diameter of a calcium ion is 205 pm
31. a. change in color: a fence being painted (physical), iron rusting (chemical)
b. change in temperature: sidewalk in the sun (physical), exothermic reaction from two elements reacting together (chemical)
c. formation of a gas: water boiling (physical), HCl and zinc reacting giving off hydrogen gas bubbles (chemical)
32.
a: Bromine
b: Silicon
33. The date from the fish kill mystery was based off of unusual levels of certain elements that occurred in an extreme pattern. The periodic table is like the chart of the fish kill date because it is also sorted out in a pattern.
34. Thorium and protactinium and uranium and neptunium.
Extra credit week four:
http://www.economist.com/node/17722567
The U-bend of life
The article I read was about how people's happiness changes throughout different stages of their life. When someone begins their life as an adult, they have a natural cheerful outlook. However, things go downhill from being a young adult until middle until they have a midlife crisis. After someone has their midlife crisis, they begin attaining the goal of everyone in life: happiness. Even though there minds may not be as sharp, they are getting wrinkles, their hair is turning gray, and their joints are beginning to ache, they are becoming happy. There are four main factors that are said to contribute to ones happiness: gender, personality, external circumstances, and age. Woman tend to be happier than man, but they are also more susceptible to depression. This shows that the emotions of woman are more intense than that of men. The global average of unhappiness is 46 years old. Happiness is also proven to make one healthier. When diagnosed with an illness, the stressed heal less quickly than the relaxed.
Things that tend to make people happier:
The U-bend of life
The article I read was about how people's happiness changes throughout different stages of their life. When someone begins their life as an adult, they have a natural cheerful outlook. However, things go downhill from being a young adult until middle until they have a midlife crisis. After someone has their midlife crisis, they begin attaining the goal of everyone in life: happiness. Even though there minds may not be as sharp, they are getting wrinkles, their hair is turning gray, and their joints are beginning to ache, they are becoming happy. There are four main factors that are said to contribute to ones happiness: gender, personality, external circumstances, and age. Woman tend to be happier than man, but they are also more susceptible to depression. This shows that the emotions of woman are more intense than that of men. The global average of unhappiness is 46 years old. Happiness is also proven to make one healthier. When diagnosed with an illness, the stressed heal less quickly than the relaxed.
Things that tend to make people happier:
- being married
- being educated
- being wealthy
Things that tend to make people sad:
- having children in the house
- being unemployed
Converting copper lab questions
1 a. Describe changes you observed as you heated the copper.
The copper, originally a reddish gold powder turned into a black solid chip. Once the copper was weighed after it had been heated, the mass was bigger.
b. Did the copper atoms remain in the crucible? Explain, using evidence from your observations.
Yes, the copper atoms remained in the crucible.
2 a. Were the changes you observed physical changes or chemical changes?
They were chemical changes and physical changes
b. What observational evidence leads you to that conclusion?
They were chemical changes because there was a change in odor, a change in color, and a change in mass. The physical changes were the change from a powder into a solid.
3 a. How did the mass of the crucible contents change after you heated the copper?
The mass got heavier by .08 g
b. Explain why the mass of the crucible contents changed in that manner.
The mass got heavier because the copper became oxidized.
Wednesday, July 6, 2011
Post bar graph questions
1. In the first graph, there is a trend of the bar changing from very high to low. In the second graph, it is apparent that the boiling points follow the same pattern as the oxygen.
2. Yes, they are consistent with earlier found patterns because it switches between nonmetals and metals, as it does on the periodic table, and the boiling points also shift as they do on the periodic table.
3. It is called a periodic table because the elements have a repeating pattern.
4. The elements with the highest oxide numbers on the periodic table are surrounding the noble gasses on the far right of the table.
5. The elements with the highest boiling points are on the far right and far left of the periodic table.
6. The elements with higher boiling points have higher oxide levels.
7. Krypton should have to lowest boiling point because it is a noble gas. All noble gasses have low boiling points. A reason for this is since they are gasses, there atoms are not as tightly bound, making it easier to boil.
8. Gallium should have the lowest boiling point, and then the rest will have boiling points corresponding to their oxide levels.
2. Yes, they are consistent with earlier found patterns because it switches between nonmetals and metals, as it does on the periodic table, and the boiling points also shift as they do on the periodic table.
3. It is called a periodic table because the elements have a repeating pattern.
4. The elements with the highest oxide numbers on the periodic table are surrounding the noble gasses on the far right of the table.
5. The elements with the highest boiling points are on the far right and far left of the periodic table.
6. The elements with higher boiling points have higher oxide levels.
7. Krypton should have to lowest boiling point because it is a noble gas. All noble gasses have low boiling points. A reason for this is since they are gasses, there atoms are not as tightly bound, making it easier to boil.
8. Gallium should have the lowest boiling point, and then the rest will have boiling points corresponding to their oxide levels.
p. 130, #13-25
13.
a. row: (horizontal) periods that are grouped according to the increase in atomic number
b. column: (vertical) groups that are organized by elements with similar properties
14.
. Hydrogen (H)
. Sodium (Na)
15.
a: Noble gasses are located on the far left side of the periodic table - the last group
b: Noble gasses are all in a gas state at room temperature
c: Noble gases are all nonreactive with other elements
16.
a. Mg and F: MgF2
b. Ga and P: GaP
17. My estimated melting point of K is about 68.5 degrees celsius. I found this by averaging 98 degrees celsius and 39 degrees celsius.
18. I would expect the boiling point of iodine to be higher than that of chlorine because iodine has a higher atomic number than chlorine.
19. See on paper
20. See on paper
21. If the lead atom gained two protons to make the ion, it would have changed into another element. If the number of protons changes, the element transforms into another element. The only way an ion can be formed is through the loss or gaining of electrons. The way that the lead ion was formed was by losing two electrons.
22.
a:
- Be: 9
- N: 14
- Ne: 20
b: Carbon has two isotopes
23. No, the mass number does not prove that there is a new element. In order for the element to be added to the periodic table, we must be aware of its physical and chemical properties along with the number of protons, neutrons, and electrons.
24. The mass of an electron is much less than the mass of a proton and a neutron. It does not contribute that much to the atomic mass.
25.
. Mg-24: protons: 12 neutrons: 12
. Mg-25: protons: 12 neutrons: 13
. Mg-26: protons: 12 neutrons: 14
a. row: (horizontal) periods that are grouped according to the increase in atomic number
b. column: (vertical) groups that are organized by elements with similar properties
14.
. Hydrogen (H)
. Sodium (Na)
15.
a: Noble gasses are located on the far left side of the periodic table - the last group
b: Noble gasses are all in a gas state at room temperature
c: Noble gases are all nonreactive with other elements
16.
a. Mg and F: MgF2
b. Ga and P: GaP
17. My estimated melting point of K is about 68.5 degrees celsius. I found this by averaging 98 degrees celsius and 39 degrees celsius.
18. I would expect the boiling point of iodine to be higher than that of chlorine because iodine has a higher atomic number than chlorine.
19. See on paper
20. See on paper
21. If the lead atom gained two protons to make the ion, it would have changed into another element. If the number of protons changes, the element transforms into another element. The only way an ion can be formed is through the loss or gaining of electrons. The way that the lead ion was formed was by losing two electrons.
22.
a:
- Be: 9
- N: 14
- Ne: 20
b: Carbon has two isotopes
23. No, the mass number does not prove that there is a new element. In order for the element to be added to the periodic table, we must be aware of its physical and chemical properties along with the number of protons, neutrons, and electrons.
24. The mass of an electron is much less than the mass of a proton and a neutron. It does not contribute that much to the atomic mass.
25.
. Mg-24: protons: 12 neutrons: 12
. Mg-25: protons: 12 neutrons: 13
. Mg-26: protons: 12 neutrons: 14
Metal or Nonmetal Lab
Metal or Nonmetal – Lab Report
July 5th, 2011
Oliver Ghadoushi, Eva Nazar
Summer School 2011 – Chemistry
Dr. Forman
____________________________
Purpose of lab: investigate several properties of seven given elements and decide if each is a metal, non-metal, or a metalloid
Abstract:
The purpose of this lab was to observe 7 different samples and record the appearance of each element (color, luster, form) and test for conductivity. In the end of this experiment, we are expected to be able to determine whether the sample was a metal or nonmetal. We did this by hammering the substance, connecting the substance to a circuit with a light bulb, and dropping in 15-20 drops of HCl and CuCl2 The tools we used in this experiment were two different well plates, a hammer, a small spoon, and HCl and CuCl2. The first thing we did was crush the different substances with the hammer to test whether they were malleable or brittle. Six of the samples were brittle while only one was malleable. When we tested the samples for conductivity, most of the samples were conductors. This showed us that most likely more than half of the samples were metals. We then observed the reactivity of these samples with hydrochloric acid and copper (II) chloride. This helped us in determining whether it was a metal, metalloid, or nonmetal because we know that metals tend to be very chemically reactive.
Procedures:
-Created data table to guide and record various data’s encountered in investigation
-Given each element, write letter of substance on paper corresponding to product
-Collect and try to crush each metal given on a separate piece of paper on table, crush and analyze overall appearance of each element (color and form)
-Continue same procedure with each substance given and record on data table
-After all are complete, take each crushed substance and place in corresponding well in an organized manner
-Drop 15-20 drops of copper chloride (CuCl2) in each of the 7 wells (A-G)
-Observe and watch any unique reaction to each substance, analyze as it goes
-Test reactivity with acid, add 15-20 drops of HCl to each of the seven wells
-Observe and watch any reaction, analyze and record result
-Clean area, wash hands, and take photographs if applicable
Lab Questions:
1.
1. Appearance = Physical Property
2. Conductivity = Physical Property
3. Crushing = Physical Property
4. Copper Chloride reactivity = Chemical Property
5. Acid reactivity = Chemical Property
2. a. Samples B & G were metals
b. Samples A, D, C, F, E were nonmetals
3. The elements that were metalloids could fit into either group (F, C, D). Several did and did not conduct electricity, and others that were filled in with the acids reacted uniquely.
Data Analysis:
After observing malleability vs. brittleness, conductivity, and reactivity of the samples with HCl and CuCl2, we have determined which are metals, nonmetals, and metalloids.
sample A: metal
sample B: metal
sample C: metalloid
sample D: metalloid
sample E: nonmetal
sample F: metalloid
sample G: metal
Metals tended to always have conductivity, they were usually lustrous, and were brittle or malleable. They were reactive with either HCl or CuCl2 or both. If they were good conductors, yet they were not reactive, they were most likely metalloids. Nonmetals were nonreactive and were not conductors. For example, sample E was not a conductor and nor did it react.
July 5th, 2011
Oliver Ghadoushi, Eva Nazar
Summer School 2011 – Chemistry
Dr. Forman
____________________________
Purpose of lab: investigate several properties of seven given elements and decide if each is a metal, non-metal, or a metalloid
Abstract:
The purpose of this lab was to observe 7 different samples and record the appearance of each element (color, luster, form) and test for conductivity. In the end of this experiment, we are expected to be able to determine whether the sample was a metal or nonmetal. We did this by hammering the substance, connecting the substance to a circuit with a light bulb, and dropping in 15-20 drops of HCl and CuCl2 The tools we used in this experiment were two different well plates, a hammer, a small spoon, and HCl and CuCl2. The first thing we did was crush the different substances with the hammer to test whether they were malleable or brittle. Six of the samples were brittle while only one was malleable. When we tested the samples for conductivity, most of the samples were conductors. This showed us that most likely more than half of the samples were metals. We then observed the reactivity of these samples with hydrochloric acid and copper (II) chloride. This helped us in determining whether it was a metal, metalloid, or nonmetal because we know that metals tend to be very chemically reactive.
Procedures:
-Created data table to guide and record various data’s encountered in investigation
-Given each element, write letter of substance on paper corresponding to product
-Collect and try to crush each metal given on a separate piece of paper on table, crush and analyze overall appearance of each element (color and form)
-Continue same procedure with each substance given and record on data table
-After all are complete, take each crushed substance and place in corresponding well in an organized manner
-Drop 15-20 drops of copper chloride (CuCl2) in each of the 7 wells (A-G)
-Observe and watch any unique reaction to each substance, analyze as it goes
-Test reactivity with acid, add 15-20 drops of HCl to each of the seven wells
-Observe and watch any reaction, analyze and record result
-Clean area, wash hands, and take photographs if applicable
Lab Questions:
1.
1. Appearance = Physical Property
2. Conductivity = Physical Property
3. Crushing = Physical Property
4. Copper Chloride reactivity = Chemical Property
5. Acid reactivity = Chemical Property
2. a. Samples B & G were metals
b. Samples A, D, C, F, E were nonmetals
3. The elements that were metalloids could fit into either group (F, C, D). Several did and did not conduct electricity, and others that were filled in with the acids reacted uniquely.
Data Analysis:
After observing malleability vs. brittleness, conductivity, and reactivity of the samples with HCl and CuCl2, we have determined which are metals, nonmetals, and metalloids.
sample A: metal
sample B: metal
sample C: metalloid
sample D: metalloid
sample E: nonmetal
sample F: metalloid
sample G: metal
Metals tended to always have conductivity, they were usually lustrous, and were brittle or malleable. They were reactive with either HCl or CuCl2 or both. If they were good conductors, yet they were not reactive, they were most likely metalloids. Nonmetals were nonreactive and were not conductors. For example, sample E was not a conductor and nor did it react.
Tuesday, July 5, 2011
p. 130, #1-12
1.
a: physical property
b: chemical property
c: chemical property
d: physical property
2.
a: physical property
b: physical property
c: chemical property
d: chemical property
3.
a: chemical change
b: chemical change
c: physical change
d: physical change
4.
a: chemical change
b: physical change
c: chemical change
d: physical change
5.
a: It is a chemical change because it is a change in color.
b: In order for the battery to lose charge, a chemical reaction did not have to take place. The battery is still the same substance, it just doesn't have the charge anymore.
c: The oil stain is removed by a chemical reaction between the soap/stain remover and the oil on the clothing. Two non-polar substances must be used in order for the stain to go away.
d: The salad dressing naturally separates over time but it is not due to a chemical reaction and even after it has separated, it is still salad dressing.
6.
a: 1. Gathering the ingredients and tools needed to make the cookies 2. mixing the dough together 3. rolling the dough into balls and putting it on the tray 4. cooking the dough in the oven
b: 1 and 3 are physical changes and 2 and 4 are chemical changes.
7.
a: metal
b: nonmetal
c: nonmetal
d: metal
8.
a: metal
b: metalloid
c: nonmetal
d: metal
9. Boron (B) and Silicon (Si)
10.
a: brittle
b: malleable
c: brittle
d: malleable
11. They are not good conductors and they are brittle, so they would not bend well.
12. They are lustrous, malleable, and ductile.
a: physical property
b: chemical property
c: chemical property
d: physical property
2.
a: physical property
b: physical property
c: chemical property
d: chemical property
3.
a: chemical change
b: chemical change
c: physical change
d: physical change
4.
a: chemical change
b: physical change
c: chemical change
d: physical change
5.
a: It is a chemical change because it is a change in color.
b: In order for the battery to lose charge, a chemical reaction did not have to take place. The battery is still the same substance, it just doesn't have the charge anymore.
c: The oil stain is removed by a chemical reaction between the soap/stain remover and the oil on the clothing. Two non-polar substances must be used in order for the stain to go away.
d: The salad dressing naturally separates over time but it is not due to a chemical reaction and even after it has separated, it is still salad dressing.
6.
a: 1. Gathering the ingredients and tools needed to make the cookies 2. mixing the dough together 3. rolling the dough into balls and putting it on the tray 4. cooking the dough in the oven
b: 1 and 3 are physical changes and 2 and 4 are chemical changes.
7.
a: metal
b: nonmetal
c: nonmetal
d: metal
8.
a: metal
b: metalloid
c: nonmetal
d: metal
9. Boron (B) and Silicon (Si)
10.
a: brittle
b: malleable
c: brittle
d: malleable
11. They are not good conductors and they are brittle, so they would not bend well.
12. They are lustrous, malleable, and ductile.
Wednesday, June 29, 2011
Water pollution vs. Water shortage: which one is more dangerous?
After all the research and studying I have done in Dr. Forman's class, I still agree with my original statement, that water pollution is still far more dangerous than water shortage. Watching the movie "Flow" reinforced my thoughts even more. As life goes on, on Earth, our water is not going to get any cleaner. With the populations growing and the water being recycled over and over again, the water is just getting more foul and impure. There will never be a complete lack of water due to the highly organized and developed hydrologic water cycle. Our only version of a water shortage would be having a water shortage in our specific area. In a situation like that, the different regions in the world would just have to learn how to cooperate together and share water. It would teach the world priority, putting a greater importance on everyone's survival rather than on specific company's taking the water for their own money. In a situation where the water is dirty and toxic, no matter how much water we have, we still cannot drink it. One sip of contaminated water could kill someone immediately, and has done so in the past. However, one can live with a little amount of water for a short amount of time until they can next acquire pure water. The main issue that needs to be solved is the supervision of the purification of water in municipal water plants. There should not be as many pathogens in our tap water as there are, and the simple determined care of a group of people to protect the world can greatly help this problem of unsafe water.
Tuesday, June 28, 2011
Eva's tutorial on evaporation
Hi, if you liked my first tutorial, I guarantee that you will find this lesson on the arguably most important part of the hydrologic cycle helpful! I am here to teach all of you about evaporation.
Evaporation is the vaporization of a liquid that occurs on the surface of water. It is transferred from the ground or a water mass to the atmospheric gasses, where it will then be condensed and eventually precipitate back to the ground, where the cycle will continue on for as long as we can predict. The sun serves as thermal energy for the water, causing it to evaporate. The water gets heated, causing the molecules to move faster until they rise from the surface of the water source. Energy breaks the bonds that hold water molecules together, which is why water easily evaporates at the boiling point but evaporaties much more slowly at the freezing point. 90% of moisture in the atmosphere via evaporation comes from oceans, seas, lakes, and rivers. (the other 10% is from plant transpiration)
Three factors affect the rate of evaporation:
1. wind speed: the higher the wind speed, the more evaporation
2. temperature: the higher the temperature, the more evaporation
3. humidity: the lower the humidity, the more evaporation
Evaporation also helps us when we need to separate something from water. We do not need a distillation apparatus like we have seen in class in order to separate water from another substance. It can be done ourselves. For example, if you are stuck on an island and need salt, you can put the ocean water in a bowl in the sun and wait for the sun to evaporate the water. The salt can not evaporate because they have different boiling points, and you will be left with usable salt.
Evaporation is the vaporization of a liquid that occurs on the surface of water. It is transferred from the ground or a water mass to the atmospheric gasses, where it will then be condensed and eventually precipitate back to the ground, where the cycle will continue on for as long as we can predict. The sun serves as thermal energy for the water, causing it to evaporate. The water gets heated, causing the molecules to move faster until they rise from the surface of the water source. Energy breaks the bonds that hold water molecules together, which is why water easily evaporates at the boiling point but evaporaties much more slowly at the freezing point. 90% of moisture in the atmosphere via evaporation comes from oceans, seas, lakes, and rivers. (the other 10% is from plant transpiration)
Three factors affect the rate of evaporation:
1. wind speed: the higher the wind speed, the more evaporation
2. temperature: the higher the temperature, the more evaporation
3. humidity: the lower the humidity, the more evaporation
Evaporation also helps us when we need to separate something from water. We do not need a distillation apparatus like we have seen in class in order to separate water from another substance. It can be done ourselves. For example, if you are stuck on an island and need salt, you can put the ocean water in a bowl in the sun and wait for the sun to evaporate the water. The salt can not evaporate because they have different boiling points, and you will be left with usable salt.
#1-9, 18-22
1. See paper
2.
Evaporation: removes nearly all dissolved substances (dissolved heavy metals, minerals, or molecular substances)
Precipitation: pure water vapor condenses and falls as either rain or snow, which is the purest water on Earth.
Sand and gravel filtration: pure rainwater goes through sand and gravel when it reaches the ground and the sand and gravel serves as a filter, removing nearly all suspended matter in the water.
3. Aluminum hydroxide causes the water to clump together and sink to the bottom. It forms a sticky, jellylike substance that traps and later removes the suspended particles. They obtain the water that is now free of suspended particles by sand filtration.
4. CaO is sometimes added in the final steps of municipal water treatment to neutralize acidic water, which raises its pH to the acceptable level for drinking.
5. There is a limit of 1 ppm of fluoride that can be added to water. The purpose of the fluoride is to reduce tooth decay.
6. The bacterial in chlorinated drinking water has been killed compared to untreated water which may very likely still contain diseases and microorganisms. The bad taste of the chlorinated water is worth the safety that it brings us.
7. The disadvantage is that THMs can develop in over-chlorinated water and this is known to cause cancer in very high concentrations.
8. Even though the water that comes down the stream is initially pure as rain or snow, once it hits the ground it is immediately contaminated. The water could carry diseases from the ground, bacteria, or from plants and animals.
9.
Charcoal filter: charcoal filtration can remove most organic compounds from water (including THM)
Ozone or an ultraviolet light: can completely eliminate chlorine, however it is not effective once the water leaves the ultraviolet light.
18. It would be very hard to get pure water because evaporation is a very effective way of naturally filtering water of all impurities. Clean water would become much rarer and more expensive because more technology would have to be used in order to make pure water.
19.If water could not turn into a gas, it would not be able to evaporate. If water could not be a liquid, there would be nothing to drink and there would not be any rain or snow. There would not be pure water. Mostly, humans would not be able to live if there was not water because it is an essential liquid that we need to survive.
20. It does not completely prohibit the use of chlorine because chlorine can be very benefitting towards us because it protects us from catching water-bourn diseases. If the amount of THM is relatively small, it is not very harmful to us.
21.
Evaporation is very similar to water distillation. Water is being turned into vapor as a purifying method in both processes. Sand and gravel filtration is similar to the sand filtration we did in the lab, along with charcoal filtration which we performed in our experiment and is also naturally occurring on Earth.
22.
a. one day: 1 ppm
b. one week: 7 ppm
c. one year: 365 ppm
2.
Evaporation: removes nearly all dissolved substances (dissolved heavy metals, minerals, or molecular substances)
Precipitation: pure water vapor condenses and falls as either rain or snow, which is the purest water on Earth.
Sand and gravel filtration: pure rainwater goes through sand and gravel when it reaches the ground and the sand and gravel serves as a filter, removing nearly all suspended matter in the water.
3. Aluminum hydroxide causes the water to clump together and sink to the bottom. It forms a sticky, jellylike substance that traps and later removes the suspended particles. They obtain the water that is now free of suspended particles by sand filtration.
4. CaO is sometimes added in the final steps of municipal water treatment to neutralize acidic water, which raises its pH to the acceptable level for drinking.
5. There is a limit of 1 ppm of fluoride that can be added to water. The purpose of the fluoride is to reduce tooth decay.
6. The bacterial in chlorinated drinking water has been killed compared to untreated water which may very likely still contain diseases and microorganisms. The bad taste of the chlorinated water is worth the safety that it brings us.
7. The disadvantage is that THMs can develop in over-chlorinated water and this is known to cause cancer in very high concentrations.
8. Even though the water that comes down the stream is initially pure as rain or snow, once it hits the ground it is immediately contaminated. The water could carry diseases from the ground, bacteria, or from plants and animals.
9.
Charcoal filter: charcoal filtration can remove most organic compounds from water (including THM)
Ozone or an ultraviolet light: can completely eliminate chlorine, however it is not effective once the water leaves the ultraviolet light.
18. It would be very hard to get pure water because evaporation is a very effective way of naturally filtering water of all impurities. Clean water would become much rarer and more expensive because more technology would have to be used in order to make pure water.
19.If water could not turn into a gas, it would not be able to evaporate. If water could not be a liquid, there would be nothing to drink and there would not be any rain or snow. There would not be pure water. Mostly, humans would not be able to live if there was not water because it is an essential liquid that we need to survive.
20. It does not completely prohibit the use of chlorine because chlorine can be very benefitting towards us because it protects us from catching water-bourn diseases. If the amount of THM is relatively small, it is not very harmful to us.
21.
Evaporation is very similar to water distillation. Water is being turned into vapor as a purifying method in both processes. Sand and gravel filtration is similar to the sand filtration we did in the lab, along with charcoal filtration which we performed in our experiment and is also naturally occurring on Earth.
22.
a. one day: 1 ppm
b. one week: 7 ppm
c. one year: 365 ppm
Solubility Lab Report: The Metals
ABSTRACT:
The objective of the solubility lab was to test the solubility of succinic acid (C4H604) at three different temperatures. Our main concern at the beginning of the lab was working with this slightly toxic acid. This placed much importance on being very careful and listening to and following instructions thoroughly. Although this lab may seem simple, one mistake may easily falsely change the results. In order to be safe, we wore latex gloves at all times and only handled the test tubes with tongs to protect us from the heat. Going into this experiment, we knew that the solubility of succinic acid would rise with temperature because succinic acid is a solid at room temperature; therefore, we knew if our results showed the solubility going down, that a mistake must have been made. In this experiment, we used a lot of laboratory equipment: a plastic weighing boat, a 400 mL beaker to heat the water, six test tubes, a stirring rod, a thermometer, a graduated cylinder (for measuring degrees in celsius), a scale, a beaker tong, a scale, a large beaker to cool the water in an ice bath, and a heater. First, we added 300 mL of water to our beaker, heated it to 45°C on the heater, added 4 grams of succinic acid and 15 mL of water to a test tube, and placed it in the heated water bath of the beaker. After the solution had been stirred for seven minutes in 30 second intervals, we put the test tube in a cold iced water bath for two minutes and then let it sit in room temperature in the beaker stand for five more minutes as the solute settled to the bottom of the test tube. We measured the solute after five minutes and repeated this process with 55°C and 65°C. At the end of the whole procedure, we recorded our data and found our average solute measurement (11.66 mm of succinic acid).
PROCEDURE:
Our first step to begin the process was to organize all of our laboratory equipment carefully; any mistakes to the seemingly simple process could lead to inaccurate data and disorganization. At first, our group, The Metals, had trouble with our heater and soon found it was broken. We began the lab experiment with what felt like chaos, but once we had a working heater and all of our equipment laid out in front of us, the procedure went smoothly! To begin the actual procedure, we filled our 400mL beaker with 300mL of tap water. We then placed it on the water heater that, and turned it on to its highest setting, 6. The reason why we set it to its highest setting was to get the water heated as quickly as possible, for due to our earlier mishap with the broken heater, we really needed to regain momentum. We placed our thermometer into the beaker, and once it reached our first temperature, 45°C, we lowered the setting on the heater, in order to maintain the heat of the water. We used the weighing boat and a very sensitive scale to carefully measure out 4 grams of succinic acid (C4H6O4) three times. We placed each 4 gram measurement of the succinic acid into 3 different test tubes and added 15 (not 20 due to the small test tubes) mL of water to each tube; by doing this, we would be prepared for each step of the process on time. Due to some confusion, we placed two tubes into the heated beaker, and although using the thermometer we were able to measure the heat of the tap water in the beaker to 45°C, the solution within the test tubes remained at 43°C; this was okay, however, because as long as the temperature of the succinic acid solution was within 2°C of the target temperature, it was acceptable. For 7 minutes, every 30 seconds we would use a stirring rod to mix the succinic acid solutions in hopes of increasing the solubility. After seven minutes had passed, we used the beaker tongs to remove the test tube from the water. We then extracted the liquid from the tube with a beral pipet and put it in a new, clean test tube (leaving the un-disolved solute in the original test tube). Then, we placed the new test tube into an iced water bath. Our test tube sat in the water bath for two minutes, and after two minutes, we took it out of the cold water and put it into a test tube rack to sit in room temperature for five minutes. At this time, our solution appeared to be clear. After waiting five minutes, the solution was still clear; therefore, due to our lack of solute, 0 mm, our group was able to conclude that succinic acid was practically insoluble at 45°C. Next, we increased the heat of the heater in order to raise the temperature of both the tap water within the beaker and the solution within the test tube to 55°C. Using the thermometer, we found that we were able to obtain a 55°C temperature in the water in the beaker, and a 54°C temperature in the succinic acid solution. Again, we used a stirring rod to mix the solution for for 7 minutes in thirty second intervals, in order to mix the solute into our distilled water solvent. After seven minutes had passed, we used our beaker tongs to remove the test tube from the heated water. We extracted the liquid from the tube with a beral pipet and put it in a new, clean test tube (leaving the un-disolved solute in the original test tube). Then, we placed the new test tube into our iced water bath for two minutes. This time, however, when we took the test tube out of the water bath, we noticed significant amounts of solute settling to the bottom of the tube. After five minutes of sitting in the test tube holder at room temperature, there was 15 mm of solute at the bottom of the tube. Finally, we were ready for our last portion of the procedure, finding the solubility of succinic acid in 15 mL water at 65°C. Since we had not placed our prepared test tube of distilled water and four grams of succinic acid in the beaker atop the heater in the beginning, we had to spend a bit more time heating our test tube. Once we brought the heat of both the water in the beaker and the water within the test tube to 65°C, (and repeatedly used the thermometer to check the temperatures of the water in the beaker and the succinic acid solution), we lowered the setting on the heater from 6 to about 1. We were then ready to begin the process. We repeated the process of using a stirring rod to mix the succinic acid solution for 7 minutes in thirty second intervals. After seven minutes had passed and the distilled water solvent was as mixed with succinic acid as it could be, we used our beaker tongs to remove the test tube from the heated water. We extracted the liquid from the tube with a beral pipet and put it in a new, clean test tube (leaving the un-dissolved solute in the original test tube). Then, we placed the new test tube into our iced water bath for two minutes. By the end of the two minutes, we noticed a more solute settling to the bottom of our test tube than the amount that settled in the solution created at 55°C. With this observation, we knew we were getting (semi) accurate data. After five minutes of sitting in the test tube rack, we measured 20 mm of succinic acid settled to the bottom of the tube. After carefully recording all of our data and observations, we were ready to clean up all of the equipment and our area, and prepare to find our average, and the class average of crystal height obtained at each temperature.
Water temperature being measured:
Solubility of succinic acid: From left: 45°C, 55°C, 65°C:
OVERVIEW OF RESULTS:
Us, The Metals:
-Solubility of succinic acid at 45°C: 0mm of settled succinic acid at the bottom of the test tube; 0mm solubility.
-Solubility of succinic acid at 55°C: 15mm of settled succinic acid at the bottom of the test tube; 15mm solubility.
-Solubility of succinic acid at 65°C: 20mm of settled succinic acid at the bottom of the test tube; 20mm solubility.
Our Average (of all three temperatures): 11.66mm solubility
Class Average: Since only two of the groups successfully obtained three sets of data for each temperature, 45°C, 55°C, and 65°C, we only included two groups, The Acids and The Metals, in our calculations for the class average.
-Solubility of succinic acid at 45°C: 1.5mm of settled succinic acid at the bottom of the test tube; 1.5mm solubility.
-Solubility of succinic acid at 55°C: 25mm of settled succinic acid at the bottom of the test tube; 25mm solubility.
-Solubility of succinic acid at 65°C: 28mm of settled succinic acid at the bottom of the test tube; 28mm solubility.
DATA ANALYSIS:
1. Find the mean crystal height obtained by your entire class for each temperature reported.
Because only two of the groups successfully obtained three sets of data for each temperature, 45°C, 55°C, and 65°C, we only included two groups, The Acids and The Metals, in our calculations for the class average. For the procedure executed to find solubility of succinic acid at 45°C, our group, The Metals, measured 0 mm of settled succinic acid at the bottom of the test tube; 0 mm solubility. The Acids measured 3 mm settled succinic acid at the bottom of the test tube; 3 mm solubility. The average of the two groups at 45°C was 1.5 mm settled succinic acid at the bottom of the test tube; 1.5 mm solubility. For the procedure executed to find solubility of succinic acid at 55°C, The Metals measured 15 mm of settled succinic acid at the bottom of the test tube, or 15 mm solubility, and The Acids measured 35 mm settled succinic acid at the bottom of the test tube, or 35 mm solubility. The average of the two groups at 55°C was 25 mm settled succinic acid at the bottom of the test tube; 25 mm solubility. The last test we conducted was to find solubility of succinic acid at 65°C. Once again, The Metals measured less than The Acids, measuring 20 mm of settled succinic acid at the bottom of the test tube, or 20 mm solubility, while the Acids measured 36 mm of settled succinic acid at the bottom of the test tube, or 36 mm solubility. The average of 65°C was 28 mm of settled succinic acid at the bottom of the test tube; 28 mm solubility.
2. Plot the mean crystal height in millimeters (y-axis) versus the water temperature in degrees Celsius (x-axis).
QUESTIONS:
1. Why is it useful to collect data from more than one trial at a particular temperature?
It is useful to do more than one trial at a particular temperature because results could vary every time due to various factors, such as small changes in temperature, the amount of time spent and intensity of mixing the solution, and the amount of time that the solution is left to sit in the hot water, the ice water, and in room temperature.
2. How did you make use of the properties of a saturated solution at different temperatures?
Since we knew that succinic acid is a solid solute and not a gas, we entered the procedure with the awareness that when the temperature of the water was risen, the solubility of the succinic acid should have risen as well. Although we did not run into the situation of solubility decreasing when the temperature was risen, if we had, this knowledge would have kept us from continuing the procedure with false data. Knowing that a supersaturated solution, if disturbed and cooled, rebalances itself and loses extra solute particles, it was interesting to see how many solutes sank to the bottom of the test tubes when the tubes were put in ice baths.
3. Did all the succinic acid that originally dissolved in the water crystallize out of the solution? Provide evidence to support your answer.
Yes, by cooling the clear solution in an ice bath after separating it from its original test tube and then allowing it to sit in room temperature for five minutes, we re-crystallized all of the succinic acid that originally dissolved in the heated water. By doing this, we were able to see the solubility of the succinic acid in each given temperature.
4. Given pooled class data, did you have enough data points to make a reliable solubility curve for succini acid? Would the curve be good enough to make useful predictions about succinic acid solubility at temperatures you have not yet investigated? Explain your answer.
No. Only two of the groups, The Metals and The Acids, actually completed the experiment with solubility data for each temperature. Because of this, we were only able to use these groups to average class data, even though there are many groups in the class. The curve we constructed only included the averaged data of these two groups; therefore, the curve we made would not be good enough to make useful predictions about succinic acid solubility at temperatures we have not yet investigated.
5. What procedures in this investigation could lead to errors? How would each error affect your data?
A huge error many groups made was putting the solute in the original test tube, and not the separated liquid, into the ice bath. This made these groups unable to complete their data tables. Also, wrong measurements of temperatures, too much or too little succinic acid, dirty tools, and too much or too little time being heated and cooled are all factors that would lead to errors and inaccurate data.
6. Using your knowledge of solubility, propose a different procedure for gathering data to construct a solubility curve.
A different procedure for gathering data to construct a solubility curve would be to take a substance and pour it into a beaker filled with water while mixing it at a given temperature. Once the water became a saturated solution, one would record the data, increase the temperature of the water, and repeat the procedure.
The objective of the solubility lab was to test the solubility of succinic acid (C4H604) at three different temperatures. Our main concern at the beginning of the lab was working with this slightly toxic acid. This placed much importance on being very careful and listening to and following instructions thoroughly. Although this lab may seem simple, one mistake may easily falsely change the results. In order to be safe, we wore latex gloves at all times and only handled the test tubes with tongs to protect us from the heat. Going into this experiment, we knew that the solubility of succinic acid would rise with temperature because succinic acid is a solid at room temperature; therefore, we knew if our results showed the solubility going down, that a mistake must have been made. In this experiment, we used a lot of laboratory equipment: a plastic weighing boat, a 400 mL beaker to heat the water, six test tubes, a stirring rod, a thermometer, a graduated cylinder (for measuring degrees in celsius), a scale, a beaker tong, a scale, a large beaker to cool the water in an ice bath, and a heater. First, we added 300 mL of water to our beaker, heated it to 45°C on the heater, added 4 grams of succinic acid and 15 mL of water to a test tube, and placed it in the heated water bath of the beaker. After the solution had been stirred for seven minutes in 30 second intervals, we put the test tube in a cold iced water bath for two minutes and then let it sit in room temperature in the beaker stand for five more minutes as the solute settled to the bottom of the test tube. We measured the solute after five minutes and repeated this process with 55°C and 65°C. At the end of the whole procedure, we recorded our data and found our average solute measurement (11.66 mm of succinic acid).
PROCEDURE:
Our first step to begin the process was to organize all of our laboratory equipment carefully; any mistakes to the seemingly simple process could lead to inaccurate data and disorganization. At first, our group, The Metals, had trouble with our heater and soon found it was broken. We began the lab experiment with what felt like chaos, but once we had a working heater and all of our equipment laid out in front of us, the procedure went smoothly! To begin the actual procedure, we filled our 400mL beaker with 300mL of tap water. We then placed it on the water heater that, and turned it on to its highest setting, 6. The reason why we set it to its highest setting was to get the water heated as quickly as possible, for due to our earlier mishap with the broken heater, we really needed to regain momentum. We placed our thermometer into the beaker, and once it reached our first temperature, 45°C, we lowered the setting on the heater, in order to maintain the heat of the water. We used the weighing boat and a very sensitive scale to carefully measure out 4 grams of succinic acid (C4H6O4) three times. We placed each 4 gram measurement of the succinic acid into 3 different test tubes and added 15 (not 20 due to the small test tubes) mL of water to each tube; by doing this, we would be prepared for each step of the process on time. Due to some confusion, we placed two tubes into the heated beaker, and although using the thermometer we were able to measure the heat of the tap water in the beaker to 45°C, the solution within the test tubes remained at 43°C; this was okay, however, because as long as the temperature of the succinic acid solution was within 2°C of the target temperature, it was acceptable. For 7 minutes, every 30 seconds we would use a stirring rod to mix the succinic acid solutions in hopes of increasing the solubility. After seven minutes had passed, we used the beaker tongs to remove the test tube from the water. We then extracted the liquid from the tube with a beral pipet and put it in a new, clean test tube (leaving the un-disolved solute in the original test tube). Then, we placed the new test tube into an iced water bath. Our test tube sat in the water bath for two minutes, and after two minutes, we took it out of the cold water and put it into a test tube rack to sit in room temperature for five minutes. At this time, our solution appeared to be clear. After waiting five minutes, the solution was still clear; therefore, due to our lack of solute, 0 mm, our group was able to conclude that succinic acid was practically insoluble at 45°C. Next, we increased the heat of the heater in order to raise the temperature of both the tap water within the beaker and the solution within the test tube to 55°C. Using the thermometer, we found that we were able to obtain a 55°C temperature in the water in the beaker, and a 54°C temperature in the succinic acid solution. Again, we used a stirring rod to mix the solution for for 7 minutes in thirty second intervals, in order to mix the solute into our distilled water solvent. After seven minutes had passed, we used our beaker tongs to remove the test tube from the heated water. We extracted the liquid from the tube with a beral pipet and put it in a new, clean test tube (leaving the un-disolved solute in the original test tube). Then, we placed the new test tube into our iced water bath for two minutes. This time, however, when we took the test tube out of the water bath, we noticed significant amounts of solute settling to the bottom of the tube. After five minutes of sitting in the test tube holder at room temperature, there was 15 mm of solute at the bottom of the tube. Finally, we were ready for our last portion of the procedure, finding the solubility of succinic acid in 15 mL water at 65°C. Since we had not placed our prepared test tube of distilled water and four grams of succinic acid in the beaker atop the heater in the beginning, we had to spend a bit more time heating our test tube. Once we brought the heat of both the water in the beaker and the water within the test tube to 65°C, (and repeatedly used the thermometer to check the temperatures of the water in the beaker and the succinic acid solution), we lowered the setting on the heater from 6 to about 1. We were then ready to begin the process. We repeated the process of using a stirring rod to mix the succinic acid solution for 7 minutes in thirty second intervals. After seven minutes had passed and the distilled water solvent was as mixed with succinic acid as it could be, we used our beaker tongs to remove the test tube from the heated water. We extracted the liquid from the tube with a beral pipet and put it in a new, clean test tube (leaving the un-dissolved solute in the original test tube). Then, we placed the new test tube into our iced water bath for two minutes. By the end of the two minutes, we noticed a more solute settling to the bottom of our test tube than the amount that settled in the solution created at 55°C. With this observation, we knew we were getting (semi) accurate data. After five minutes of sitting in the test tube rack, we measured 20 mm of succinic acid settled to the bottom of the tube. After carefully recording all of our data and observations, we were ready to clean up all of the equipment and our area, and prepare to find our average, and the class average of crystal height obtained at each temperature.
Water temperature being measured:
Solubility of succinic acid: From left: 45°C, 55°C, 65°C:
OVERVIEW OF RESULTS:
Us, The Metals:
-Solubility of succinic acid at 45°C: 0mm of settled succinic acid at the bottom of the test tube; 0mm solubility.
-Solubility of succinic acid at 55°C: 15mm of settled succinic acid at the bottom of the test tube; 15mm solubility.
-Solubility of succinic acid at 65°C: 20mm of settled succinic acid at the bottom of the test tube; 20mm solubility.
Our Average (of all three temperatures): 11.66mm solubility
Class Average: Since only two of the groups successfully obtained three sets of data for each temperature, 45°C, 55°C, and 65°C, we only included two groups, The Acids and The Metals, in our calculations for the class average.
-Solubility of succinic acid at 45°C: 1.5mm of settled succinic acid at the bottom of the test tube; 1.5mm solubility.
-Solubility of succinic acid at 55°C: 25mm of settled succinic acid at the bottom of the test tube; 25mm solubility.
-Solubility of succinic acid at 65°C: 28mm of settled succinic acid at the bottom of the test tube; 28mm solubility.
DATA ANALYSIS:
1. Find the mean crystal height obtained by your entire class for each temperature reported.
Because only two of the groups successfully obtained three sets of data for each temperature, 45°C, 55°C, and 65°C, we only included two groups, The Acids and The Metals, in our calculations for the class average. For the procedure executed to find solubility of succinic acid at 45°C, our group, The Metals, measured 0 mm of settled succinic acid at the bottom of the test tube; 0 mm solubility. The Acids measured 3 mm settled succinic acid at the bottom of the test tube; 3 mm solubility. The average of the two groups at 45°C was 1.5 mm settled succinic acid at the bottom of the test tube; 1.5 mm solubility. For the procedure executed to find solubility of succinic acid at 55°C, The Metals measured 15 mm of settled succinic acid at the bottom of the test tube, or 15 mm solubility, and The Acids measured 35 mm settled succinic acid at the bottom of the test tube, or 35 mm solubility. The average of the two groups at 55°C was 25 mm settled succinic acid at the bottom of the test tube; 25 mm solubility. The last test we conducted was to find solubility of succinic acid at 65°C. Once again, The Metals measured less than The Acids, measuring 20 mm of settled succinic acid at the bottom of the test tube, or 20 mm solubility, while the Acids measured 36 mm of settled succinic acid at the bottom of the test tube, or 36 mm solubility. The average of 65°C was 28 mm of settled succinic acid at the bottom of the test tube; 28 mm solubility.
2. Plot the mean crystal height in millimeters (y-axis) versus the water temperature in degrees Celsius (x-axis).
QUESTIONS:
1. Why is it useful to collect data from more than one trial at a particular temperature?
It is useful to do more than one trial at a particular temperature because results could vary every time due to various factors, such as small changes in temperature, the amount of time spent and intensity of mixing the solution, and the amount of time that the solution is left to sit in the hot water, the ice water, and in room temperature.
2. How did you make use of the properties of a saturated solution at different temperatures?
Since we knew that succinic acid is a solid solute and not a gas, we entered the procedure with the awareness that when the temperature of the water was risen, the solubility of the succinic acid should have risen as well. Although we did not run into the situation of solubility decreasing when the temperature was risen, if we had, this knowledge would have kept us from continuing the procedure with false data. Knowing that a supersaturated solution, if disturbed and cooled, rebalances itself and loses extra solute particles, it was interesting to see how many solutes sank to the bottom of the test tubes when the tubes were put in ice baths.
3. Did all the succinic acid that originally dissolved in the water crystallize out of the solution? Provide evidence to support your answer.
Yes, by cooling the clear solution in an ice bath after separating it from its original test tube and then allowing it to sit in room temperature for five minutes, we re-crystallized all of the succinic acid that originally dissolved in the heated water. By doing this, we were able to see the solubility of the succinic acid in each given temperature.
4. Given pooled class data, did you have enough data points to make a reliable solubility curve for succini acid? Would the curve be good enough to make useful predictions about succinic acid solubility at temperatures you have not yet investigated? Explain your answer.
No. Only two of the groups, The Metals and The Acids, actually completed the experiment with solubility data for each temperature. Because of this, we were only able to use these groups to average class data, even though there are many groups in the class. The curve we constructed only included the averaged data of these two groups; therefore, the curve we made would not be good enough to make useful predictions about succinic acid solubility at temperatures we have not yet investigated.
5. What procedures in this investigation could lead to errors? How would each error affect your data?
A huge error many groups made was putting the solute in the original test tube, and not the separated liquid, into the ice bath. This made these groups unable to complete their data tables. Also, wrong measurements of temperatures, too much or too little succinic acid, dirty tools, and too much or too little time being heated and cooled are all factors that would lead to errors and inaccurate data.
6. Using your knowledge of solubility, propose a different procedure for gathering data to construct a solubility curve.
A different procedure for gathering data to construct a solubility curve would be to take a substance and pour it into a beaker filled with water while mixing it at a given temperature. Once the water became a saturated solution, one would record the data, increase the temperature of the water, and repeat the procedure.
Monday, June 27, 2011
Eva's lesson: Naming ionic compounds
This is my tutorial on how to name ionic compounds in Dr. Forman's ChemCom class. First, I will list some basic information that makes the process more understandable. Second, I will discuss the naming of cations and anions.
Key facts:
Key facts:
- Cations: positively charged ions
- Anions: negatively charged ions
- A cation is always named before an anion in an ionic compound
- Parenthesis go around a polyatomic ion
Cations:
- When metals only have one possible charge, the name of the metal is used
- When metals can have more than one charge, the name of the metal is followed by the number of the ionic charge in roman numerals.
- Example: Copper (II) - This version of copper has a cation of a +2 charge
- The suffix -ous is used for the lowest lowest level of the ion and -ic s used for the highest ion.
- Example: Cu+ is called cuprous while Cu2+ is called cupric.
Here is a chart for further clarification:
Anions:
- Anions have the suffix -ide
- Example: Oxide (o2-)
- Polyatomic ions that include oxygen have the suffixes -ate or -ite. -ate means that there is more oxygen in the anion than -ite. Therefore, the anions with the bigger charges end in -ate while the smaller ones (ex. 1-) end in -ite.
#20-27, 33, 35
20.
a. A soft drink is more acidic than a tomato.
b. Black coffee is more acidic than water.
c. Milk of magnesia is more acidic than household ammonia.
21. It is 20 times more acidic.
22. If the pH of the water that the fish lives in is acidic, it can impair the ability for the fish to reproduce. If the pH is basic, the water can dissolve the skin and the scales of the fish. It is important the the pH remains from 5.0-9.0.
23. Water molecules are polar and water is a polar solvent. Polar solvents such as water dissolve polar substances. Polar molecules have an uneven distribution of electrical charge and nonpolar molecules do not have a separation of charge. Nonpolar molecules do not dissolve very well in polar solvents, instead, they dissolve in nonpolar solvents.
24. I would not select water or ethanol because they are both polar and a nonpolar solvent would be needed to dissolve a nonpolar molecular substance. I would choose lamp oil because it is nonpolar.
25. NaCl dissolves in water because NaCl is a polar molecular compound and water is a polar solvent. It would not dissolve in cooking oil because cooking oil is nonpolar.
26. "like dissolves like" refers to the idea that polar solvents dissolve polar molecular substances and nonpolar solvents dissolve nonpolar molecular substances. It is the matching pattern of solubility.
27. You cannot thoroughly clean greasy dishes with plain water because the polar water can not dissolve the nonpolar grease and oil. In order to effectively clean greasy dishes, one would need to use a nonpolar or basic substance.
33.
a. Nonpolar moles are likely to be found in waterless hand cleaner.
b. Since waterless hand cleaners are used specifically to get the grime off of hands, they are made with nonpolar molecules instead of polar molecules. Thus, being more effective for cleaning the grease off of the mechanic's hands. The polar molecules in water are obviously not going to clean hands with nonpolar substances as well as just simply using nonpolar substances to clean their hands.
35. I would expect hydrogen to have a partial positive charge because if there is a polar bond, there must be a positive atom in the molecule in order for their to be attraction between fluorine and hydrogen. Also, from previous learning, I know that hydrogen is a common positive ion.
a. A soft drink is more acidic than a tomato.
b. Black coffee is more acidic than water.
c. Milk of magnesia is more acidic than household ammonia.
21. It is 20 times more acidic.
22. If the pH of the water that the fish lives in is acidic, it can impair the ability for the fish to reproduce. If the pH is basic, the water can dissolve the skin and the scales of the fish. It is important the the pH remains from 5.0-9.0.
23. Water molecules are polar and water is a polar solvent. Polar solvents such as water dissolve polar substances. Polar molecules have an uneven distribution of electrical charge and nonpolar molecules do not have a separation of charge. Nonpolar molecules do not dissolve very well in polar solvents, instead, they dissolve in nonpolar solvents.
24. I would not select water or ethanol because they are both polar and a nonpolar solvent would be needed to dissolve a nonpolar molecular substance. I would choose lamp oil because it is nonpolar.
25. NaCl dissolves in water because NaCl is a polar molecular compound and water is a polar solvent. It would not dissolve in cooking oil because cooking oil is nonpolar.
26. "like dissolves like" refers to the idea that polar solvents dissolve polar molecular substances and nonpolar solvents dissolve nonpolar molecular substances. It is the matching pattern of solubility.
27. You cannot thoroughly clean greasy dishes with plain water because the polar water can not dissolve the nonpolar grease and oil. In order to effectively clean greasy dishes, one would need to use a nonpolar or basic substance.
33.
a. Nonpolar moles are likely to be found in waterless hand cleaner.
b. Since waterless hand cleaners are used specifically to get the grime off of hands, they are made with nonpolar molecules instead of polar molecules. Thus, being more effective for cleaning the grease off of the mechanic's hands. The polar molecules in water are obviously not going to clean hands with nonpolar substances as well as just simply using nonpolar substances to clean their hands.
35. I would expect hydrogen to have a partial positive charge because if there is a polar bond, there must be a positive atom in the molecule in order for their to be attraction between fluorine and hydrogen. Also, from previous learning, I know that hydrogen is a common positive ion.
Sunday, June 26, 2011
p. 82-83, #9-19
9. 11 grams of sugar and 44 grams of water.
10. 15,000 ppm
11. A water molecule is polar if its hydrogen atoms are positive and its oxygen atom is negative. It is both positive and negative, resulting in in overall being neutral.
12. See paper
13.
a. K+: the negative side of the oxygen atom
b. Br-: the positive side of the hydrogen atoms
14. Heavy metals are called "heavy" because their masses are heavier than the masses of the essential metallic elements.
15. Brain damage, numbness, and staggered walk.
16.
a. lead: You can be exposed to lead if your house has been painted in the 1970s and has not been updated since.
b. mercury: You can be exposed to mercury by eating certain types of fish and shellfish.
17. Hydroxide ions are found in many bases.
18. Hydrogen is found in most acids.
19.
a. seawater: basic
b. drain cleaner: basic
c. vinegar: acidic
d. pure water: neutral
10. 15,000 ppm
11. A water molecule is polar if its hydrogen atoms are positive and its oxygen atom is negative. It is both positive and negative, resulting in in overall being neutral.
12. See paper
13.
a. K+: the negative side of the oxygen atom
b. Br-: the positive side of the hydrogen atoms
14. Heavy metals are called "heavy" because their masses are heavier than the masses of the essential metallic elements.
15. Brain damage, numbness, and staggered walk.
16.
a. lead: You can be exposed to lead if your house has been painted in the 1970s and has not been updated since.
b. mercury: You can be exposed to mercury by eating certain types of fish and shellfish.
17. Hydroxide ions are found in many bases.
18. Hydrogen is found in most acids.
19.
a. seawater: basic
b. drain cleaner: basic
c. vinegar: acidic
d. pure water: neutral
Thursday, June 23, 2011
p. 62, #1-3
1.
a. You would not notice changes in the beaker. The only changes you could see would be microscopically between the atoms. The atoms would begin to suspend.
b. See picture
2.
a. See picture
b.
i. See picture
ii. 20 grams must evaporate
3.
a. See picture
b. See picture
c. In the first picture, there is more potassium, but in the second picture there is more water than potassium. In addition, 3a has a higher concentration than 3b because there is less water.
a. You would not notice changes in the beaker. The only changes you could see would be microscopically between the atoms. The atoms would begin to suspend.
b. See picture
2.
a. See picture
b.
i. See picture
ii. 20 grams must evaporate
3.
a. See picture
b. See picture
c. In the first picture, there is more potassium, but in the second picture there is more water than potassium. In addition, 3a has a higher concentration than 3b because there is less water.
Extra credit week two:
http://www.economist.com/node/13176767
Sunny Side Up
The article I read on psychology revealed a new gene that has been found to cause depression, proving that sometime's someone's negative outlook on life can be inherited. It has been found that people who have inherited this gene are more prone to depression and more likely to attempt suicide while facing traumatic events that they can't cope with. This gene promotes the activity of a second gene, known as the serotonin transporter. Serotonin is a messenger molecule that carries signals between nerve cells, and recycles serotonin back into the cell that produced it, making it reusable. People with this gene have a reduced amount of serotonin the junctions between nerve cells.The gene was tested in individuals by a dot-probe paradigm test. This test briefly shows photographs that may be positive, negative or neutral. The people being evaluated then have to press a keypad to indicate when the dot has appeared on the screen. When the image was more distracting, the person took longer to respond to the dot. This showed doctors how distracting certain people found particular images. These tests confirmed that a person's attitude towards life is inherited.
Sunny Side Up
The article I read on psychology revealed a new gene that has been found to cause depression, proving that sometime's someone's negative outlook on life can be inherited. It has been found that people who have inherited this gene are more prone to depression and more likely to attempt suicide while facing traumatic events that they can't cope with. This gene promotes the activity of a second gene, known as the serotonin transporter. Serotonin is a messenger molecule that carries signals between nerve cells, and recycles serotonin back into the cell that produced it, making it reusable. People with this gene have a reduced amount of serotonin the junctions between nerve cells.The gene was tested in individuals by a dot-probe paradigm test. This test briefly shows photographs that may be positive, negative or neutral. The people being evaluated then have to press a keypad to indicate when the dot has appeared on the screen. When the image was more distracting, the person took longer to respond to the dot. This showed doctors how distracting certain people found particular images. These tests confirmed that a person's attitude towards life is inherited.
Wednesday, June 22, 2011
Things to review for the test
- SI metric system
- Ions
- naming ionic compounds
- Balancing equations
- The Periodic Table
- Solubility
- Dimensional Analysis
- Colloid vs. suspension vs. solution
p. 56, #1-3
1.
a. 107g of KNO3 will dissolve in 100 g of water at 60 degrees celsius
b. 45g of KCl will dissolve in 100 g of water at 60 degrees celsius
2.
a. About 20 more grams are needed to create a saturated solution at 30 degrees celsius
b. 55.6g of water are needed to dissolve 25 g of potassium nitrate
3.
a. 50g of KNO3
b. 187.5g of water would have to be added to dissolve all of the KNO3
a. 107g of KNO3 will dissolve in 100 g of water at 60 degrees celsius
b. 45g of KCl will dissolve in 100 g of water at 60 degrees celsius
2.
a. About 20 more grams are needed to create a saturated solution at 30 degrees celsius
b. 55.6g of water are needed to dissolve 25 g of potassium nitrate
3.
a. 50g of KNO3
b. 187.5g of water would have to be added to dissolve all of the KNO3
p. 82, #1-8
1. It will completely dissolve the sugar in a serving of hot tea because with some substances, as the temperature goes up so does the solubility.
2. The maximum mass of potassium chloride that will dissolve in 100 g of water at 70 degrees celsius is about 130 g.
3.
a. 100 mL water? 200 g of sugar
b. 355 mL (12 oz) water? 710 g of sugar
c. 946 mL (1 qt) water? 1892 g of sugar
4.
a. NaCl, KCL, KNO3
b. KNO3, KCL, NaCl
5. When a solution is saturated, it means that the solution contains the maximum amount of a substance that can dissolve in that amount of water. When a solution is unsaturated, it means that the solvent has not dissolved the maximum solute that it can dissolve.
6.
a. 31 g
b. It is supersaturated
c. 70g of KNO3 should form as the saturated solution cools
7.
a. Nothing will happen. If it is unsaturated, you are just adding solute to the solvent without reaching the maximum capacity.
b. It will become supersaturated or the crystal will float to the bottom.
c. It will disturb the supersaturated solution and it will collapse and crystals will form.
8. 30%
2. The maximum mass of potassium chloride that will dissolve in 100 g of water at 70 degrees celsius is about 130 g.
3.
a. 100 mL water? 200 g of sugar
b. 355 mL (12 oz) water? 710 g of sugar
c. 946 mL (1 qt) water? 1892 g of sugar
4.
a. NaCl, KCL, KNO3
b. KNO3, KCL, NaCl
5. When a solution is saturated, it means that the solution contains the maximum amount of a substance that can dissolve in that amount of water. When a solution is unsaturated, it means that the solvent has not dissolved the maximum solute that it can dissolve.
6.
a. 31 g
b. It is supersaturated
c. 70g of KNO3 should form as the saturated solution cools
7.
a. Nothing will happen. If it is unsaturated, you are just adding solute to the solvent without reaching the maximum capacity.
b. It will become supersaturated or the crystal will float to the bottom.
c. It will disturb the supersaturated solution and it will collapse and crystals will form.
8. 30%
Tuesday, June 21, 2011
What did you learn from this lab about water and about process?
I learned that not only is water differentiated based on whether it is a solution, colloid, or suspension but it is also separated according to the different ions it has. Even though distilled water, tap water, and ocean water all are simply H2O, they all have different ions and react differently to certain substances. This lab taught me how different tap water can be from distilled water because tap water contains so many more chemicals and minerals. I learned that process is very important, because if the directions are not followed properly, the results could be completely different, changing your lab entirely. The step of thoroughly cleaning the wellplates is also very important because it could mix your samples up, ruining your tests.
p. 51-52, #25-34
25. Qualitative tests are tests that test for the presence or absence of a particular substance in a sample. Quantitative tests do the opposite, determining the amount of a specific substance present in a sample.
26. A confirming test is a positive test that confirms if an ion in question is present in a sample.
27.
a. the reference solution: The point of having a reference solution is to have a sample with the known ion to be compared to the samples that we are questioning for having the ion.
b. the distilled-water blank: We use a distilled-water blank as another sample to compare to because we know that the distilled-water does not have any ions.
28. No, the student should not automatically assume that no iron is present in the sample because over time due to oxidization, iron changes color. Eventually, color may appear in the sample.
29.
a. I would use the steps from the previous lab: oil-water separation, sand filtration, and charcoal adsorption/filtration
b. Oil-water separation helps in showing us if it is a suspension because it removes the oil particles, and once the oil is removed it makes the particles more visible. By even having to do this procedure, we automatically know that it is a suspension because it contains oil particles. Sand filtration determines whether the foul water is a suspension or a colloid/solution. Once the water has been filtered through the sand, and the water is clear with barely any particles, we know that the water is a suspension. If there are still some small particles and color, we know that it is a colloid/solution because the particles were too small to be removed by the sand. Finally, charcoal adsorption will give the end result of whether the liquid is a colloid or a suspension because after the procedure is done, the Tyndall effect will either show that there are particles or that there are not (solution).
30. If you do not shake before using a medicine that directs you to do so, you are not allowing the suspension to mix properly. You may only be ingesting certain parts of the liquid, leaving some vital particles that are needed for the medicine to work at the bottom of the bottle. Also, if you take the medicine for a prolonged period of time without shaking it and then when it reaches the end of the bottle, you are putting yourself at risk for an overdose of the medication. This is so because the particles have caked at the bottom of the container, and the medicine you are taking is much more concentrated now.
31. It is useful for the element symbols to have international acceptance so that elements don't get mixed up, potentially causing a dangerous reaction. While working in a lab, you may have people from all over the world and everyone needs to be working with the same understanding of the elements and chemicals that they are experimenting with.
32. On paper
33. No, it is not possible because even water that is purified becomes contaminated by atmospheric gases in the air such as nitrogen, oxygen, and carbon dioxide.
34. H20 is a liquid, while hydrogen and oxygen are both gasses. Hydrogen needs one more electron to be stable and have a complete shell and oxygen needs two more electrons. Oxygen is also much more magnetic than hydrogen.
26. A confirming test is a positive test that confirms if an ion in question is present in a sample.
27.
a. the reference solution: The point of having a reference solution is to have a sample with the known ion to be compared to the samples that we are questioning for having the ion.
b. the distilled-water blank: We use a distilled-water blank as another sample to compare to because we know that the distilled-water does not have any ions.
28. No, the student should not automatically assume that no iron is present in the sample because over time due to oxidization, iron changes color. Eventually, color may appear in the sample.
29.
a. I would use the steps from the previous lab: oil-water separation, sand filtration, and charcoal adsorption/filtration
b. Oil-water separation helps in showing us if it is a suspension because it removes the oil particles, and once the oil is removed it makes the particles more visible. By even having to do this procedure, we automatically know that it is a suspension because it contains oil particles. Sand filtration determines whether the foul water is a suspension or a colloid/solution. Once the water has been filtered through the sand, and the water is clear with barely any particles, we know that the water is a suspension. If there are still some small particles and color, we know that it is a colloid/solution because the particles were too small to be removed by the sand. Finally, charcoal adsorption will give the end result of whether the liquid is a colloid or a suspension because after the procedure is done, the Tyndall effect will either show that there are particles or that there are not (solution).
30. If you do not shake before using a medicine that directs you to do so, you are not allowing the suspension to mix properly. You may only be ingesting certain parts of the liquid, leaving some vital particles that are needed for the medicine to work at the bottom of the bottle. Also, if you take the medicine for a prolonged period of time without shaking it and then when it reaches the end of the bottle, you are putting yourself at risk for an overdose of the medication. This is so because the particles have caked at the bottom of the container, and the medicine you are taking is much more concentrated now.
31. It is useful for the element symbols to have international acceptance so that elements don't get mixed up, potentially causing a dangerous reaction. While working in a lab, you may have people from all over the world and everyone needs to be working with the same understanding of the elements and chemicals that they are experimenting with.
32. On paper
33. No, it is not possible because even water that is purified becomes contaminated by atmospheric gases in the air such as nitrogen, oxygen, and carbon dioxide.
34. H20 is a liquid, while hydrogen and oxygen are both gasses. Hydrogen needs one more electron to be stable and have a complete shell and oxygen needs two more electrons. Oxygen is also much more magnetic than hydrogen.
Monday, June 20, 2011
How does testing water help us?
Water testing helps us because it aids in determining if the water we are drinking is safe and good for us. It provides us with the information to be able to decide whether a solution is a base or an acid, and with its usage we can make sure that the water we are drinking is neutral.
p. 51, #19-24
19.
a. carbon: 6 protons, 6 electrons
b. aluminum: 13 protons, 13 electrons
c. lead: 82 protons, 82 electrons
d. chlorine 17 protons, 17 electrons
20.
a. sulfur: not neutral
b. iron: not neutral
c. silver: neutral
d. iodine: not neutral
21.
a. anion
b. neutral
c. neutral
d. cation
e. cation
22.
a. gained two electrons
b. neither
c. neither
d. lost an electron
e. lost two electrons
23.
a. hydrogen with 1 proton and 1 electron: H
b. sodium with 11 protons and 10 electrons: Na+
c. chlorine with 17 protons and 18 electrons: Cl-
d. aluminum with 13 protons and 10 electrons: Al3+
24.
a. KI: potassium iodine
b. Ca2+ and S2-: CaS: calcium sulfide
c. Fe3+ and Br-: iron bromide (III) or FeBr-3
d. Ba2+ and OH-: Ba+OH: barium hydroxide
e. NH4+ and PO43-: sodium phosphate or (NH4)3 PO4
f. Al3+ and O2-: aluminum oxide AlO+
p. 20-21, #1-7
1. Total water volume used in three days: 802 L
2. Per person daily average use of water: 267 L
3. Check on sheet of paper
4. The range of the average daily personal water use within the class: 734 L
5. The mean: 447 L, The median: 468 L. The median seems to be more representative because there were many high numbers (for example 490 L) that were much higher than the average.
6. The average of the Buckley school students is most likely higher than the national average because we live in an advanced urban city. In addition, most residents of Los Angeles are in the upper/middle class allowing them the privileges of using more water than people in the lower classes.
7. The class average is closer than my personal average because my family is small. Usually, there are only two people living in my house and the average family is a family of four, which would require more water. My house doesn't have a garden in the back or front yard, needing very little water for watering the lawn. Also, while the water diary was being written, my family wasn't home most of the time.
2. Per person daily average use of water: 267 L
3. Check on sheet of paper
4. The range of the average daily personal water use within the class: 734 L
5. The mean: 447 L, The median: 468 L. The median seems to be more representative because there were many high numbers (for example 490 L) that were much higher than the average.
6. The average of the Buckley school students is most likely higher than the national average because we live in an advanced urban city. In addition, most residents of Los Angeles are in the upper/middle class allowing them the privileges of using more water than people in the lower classes.
7. The class average is closer than my personal average because my family is small. Usually, there are only two people living in my house and the average family is a family of four, which would require more water. My house doesn't have a garden in the back or front yard, needing very little water for watering the lawn. Also, while the water diary was being written, my family wasn't home most of the time.
Sunday, June 19, 2011
p. 50-52, #13-18
13. see picture on sheet
14.
a. which models represent elements? i, vi, iv, ii
b. which models represent compounds? iii, v
15. The chemical formula provides each chemical substance and how many atoms from each element/compound are used.
16.
a. Three hydrogen atoms, one phosphorous atom, and four oxygen atoms.
b. One sodium atom, one oxygen atom, and one hydrogen atom.
c. One sulfur atom and two. oxygen atoms
17. see picture on sheet
18.
a. NaHCO3+ HCl-->NaH20CO2
b. C6H12O6+O6-->6CO26H2O
14.
a. which models represent elements? i, vi, iv, ii
b. which models represent compounds? iii, v
15. The chemical formula provides each chemical substance and how many atoms from each element/compound are used.
16.
a. Three hydrogen atoms, one phosphorous atom, and four oxygen atoms.
b. One sodium atom, one oxygen atom, and one hydrogen atom.
c. One sulfur atom and two. oxygen atoms
17. see picture on sheet
18.
a. NaHCO3+ HCl-->NaH20CO2
b. C6H12O6+O6-->6CO26H2O
Thursday, June 16, 2011
pg. 33, #1-3
1. check picture on paper
2. The model represents a heterogeneous matter because the molecules are not uniform, and half of the molecules are shown in suspension, sinking at the bottom. The other half are floating on top. It is not distributed evenly.
3. check picture on paper
2. The model represents a heterogeneous matter because the molecules are not uniform, and half of the molecules are shown in suspension, sinking at the bottom. The other half are floating on top. It is not distributed evenly.
3. check picture on paper
Wednesday, June 15, 2011
B.4 vocab list
particulate level: level of atoms and molecules
atoms: the building blocks of matter
element: matter that is made up of only one kind of atom
compound: a substance that is composed of the atoms of two different elements linked together chemically
chemical formulas: an expression that shows the elements that are contained in a substance with the subscripts that indicate the number of atoms of each element
substance: has a uniform and definite composition as well as distinct properties
molecule: the smallest unit of a molecular compound that retains the properties of that substance
atoms: the building blocks of matter
element: matter that is made up of only one kind of atom
compound: a substance that is composed of the atoms of two different elements linked together chemically
chemical formulas: an expression that shows the elements that are contained in a substance with the subscripts that indicate the number of atoms of each element
substance: has a uniform and definite composition as well as distinct properties
molecule: the smallest unit of a molecular compound that retains the properties of that substance
1-12, p. 50
1. A physical property is property that can be observed and measured without changing the chemical makeup of the substance.
2. Three physical properties of water are it's freezing point (O degrees celsius), it's boiling point (100 degrees celsius), and it's density (1.00 g/mL at 25 degrees Celsius).
3. The density of ice is less than the density of water.
4. An example of a setting like this could be in one of the hot springs in Yellowstone National Park during the winter time. The hot springs are surrounded by ice and snow. The surrounding ice/snow might melt and becomes part of the hot spring. After it turns into a liquid state, the water molecules are moving fast enough from the intense heat, that they have reached a point that they are able to evaporate and become water vapor.
5. Heterogeneous and homogeneous mixtures are different because heterogeneous mixtures can still be separated physically and are made up of varying amounts of atoms, while homogenous mixtures are even throughout and have an equal amount of atoms. Heterogeneous mixtures also usually contain particles that settle at the bottom.
6. You need to know the density of both of the liquids to determine which one will be on top.
7.
a. a medicine accompanied by instructions to "shake before using": suspension
b. Italian salad dressing: suspension
c. mayonnaise: colloid
d. a cola soft drink: solution
e. an oil-based paint: suspension
f. milk: colloid
8. It demonstrates that the air in the room is a colloid because the beam of light bounces off of the particles in the air. In a solution, the particles are dissolved into the atoms and will not reflect the light. In a suspension, the particles are too large and cloudy and block the Tyndall effect from occurring.
9. see sketch on paper
10. It must be a colloid for the reasons presented. It can not be a suspension because particles would have settled at the bottom, and it can not be a solution because the beam of light would not have shone in the middle because in a solution, the particles are absorbed.
11. Substance is a material with a definite, uniform composition with distinct properties. Two examples are elements and compounds.
12.
a. CO: compound
b. Co: element
d. HCI: compound
d. Mg: element
e. NaHCO3: compound
f. NO: compound
g. I2: element
2. Three physical properties of water are it's freezing point (O degrees celsius), it's boiling point (100 degrees celsius), and it's density (1.00 g/mL at 25 degrees Celsius).
3. The density of ice is less than the density of water.
4. An example of a setting like this could be in one of the hot springs in Yellowstone National Park during the winter time. The hot springs are surrounded by ice and snow. The surrounding ice/snow might melt and becomes part of the hot spring. After it turns into a liquid state, the water molecules are moving fast enough from the intense heat, that they have reached a point that they are able to evaporate and become water vapor.
5. Heterogeneous and homogeneous mixtures are different because heterogeneous mixtures can still be separated physically and are made up of varying amounts of atoms, while homogenous mixtures are even throughout and have an equal amount of atoms. Heterogeneous mixtures also usually contain particles that settle at the bottom.
6. You need to know the density of both of the liquids to determine which one will be on top.
7.
a. a medicine accompanied by instructions to "shake before using": suspension
b. Italian salad dressing: suspension
c. mayonnaise: colloid
d. a cola soft drink: solution
e. an oil-based paint: suspension
f. milk: colloid
8. It demonstrates that the air in the room is a colloid because the beam of light bounces off of the particles in the air. In a solution, the particles are dissolved into the atoms and will not reflect the light. In a suspension, the particles are too large and cloudy and block the Tyndall effect from occurring.
9. see sketch on paper
10. It must be a colloid for the reasons presented. It can not be a suspension because particles would have settled at the bottom, and it can not be a solution because the beam of light would not have shone in the middle because in a solution, the particles are absorbed.
11. Substance is a material with a definite, uniform composition with distinct properties. Two examples are elements and compounds.
12.
a. CO: compound
b. Co: element
d. HCI: compound
d. Mg: element
e. NaHCO3: compound
f. NO: compound
g. I2: element
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