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
Extra credit week one:
Article:
http://www.economist.com/node/18750624
Summary:
New "smart" contact lenses are being developed that exploit the unusual characteristics of the eye that can diagnose diseases and deliver medicine to the wearer. The main disease that these contacts are being used to diagnose and treat is Glaucoma. In addition to Glaucoma, these lenses may also be developed to diagnose hypertension and brain tumors by examining the retina of the eye. They also may be advanced into being used to measure the level of cholesterol or alcohol in your blood. These contact lenses work by using embedded sensors and electronics that monitor disease and dispense drugs. Not only would they work as sensors, but they would use pixels to create a display as well on the lens. By adding tiny light-emitting elements to the contact lenses, it is possible to map digital images directly onto the patient's field of vision to create a display overlay that requires no additional screen except for the contacts. Best of all, the contact lenses that aid in treating Glaucoma are already on the market. There is a varied version of the smart contact lens that is meant to be worn continuously. Unfortunately, it is still under development and not available yet. It would be set at aiding diseases rather than just monitoring them by using sensors. The lenses would release the drugs through the eye over a long period of time, and would be released when the disease peaked. However, there are still some concerns with this innovation. The drugs may be triggered to release by false situations. For example, the drug may be directed to release by the harmless cough of someone. Another concern is that the lens may have a negative effect on the wearer's vision when the drugs are released, clouding the vision of the patient.
http://www.economist.com/node/18750624
Summary:
New "smart" contact lenses are being developed that exploit the unusual characteristics of the eye that can diagnose diseases and deliver medicine to the wearer. The main disease that these contacts are being used to diagnose and treat is Glaucoma. In addition to Glaucoma, these lenses may also be developed to diagnose hypertension and brain tumors by examining the retina of the eye. They also may be advanced into being used to measure the level of cholesterol or alcohol in your blood. These contact lenses work by using embedded sensors and electronics that monitor disease and dispense drugs. Not only would they work as sensors, but they would use pixels to create a display as well on the lens. By adding tiny light-emitting elements to the contact lenses, it is possible to map digital images directly onto the patient's field of vision to create a display overlay that requires no additional screen except for the contacts. Best of all, the contact lenses that aid in treating Glaucoma are already on the market. There is a varied version of the smart contact lens that is meant to be worn continuously. Unfortunately, it is still under development and not available yet. It would be set at aiding diseases rather than just monitoring them by using sensors. The lenses would release the drugs through the eye over a long period of time, and would be released when the disease peaked. However, there are still some concerns with this innovation. The drugs may be triggered to release by false situations. For example, the drug may be directed to release by the harmless cough of someone. Another concern is that the lens may have a negative effect on the wearer's vision when the drugs are released, clouding the vision of the patient.
Short response
#2: Which is worse? Water shortages vc Water pollution?
I believe that water pollution is more severe than water shortage, because water pollution causes water to be unusable for necessary usage. You could have endless supplies of water, however, if the water is dirty and foul, the water can barely be used. As we read throughout the chapter, our daily use of water can be limited by being careful and taking advantage of using impure water for tasks that do not involve pure water. Polluted water can be toxic and kill many people, but water shortages can be dealt with by smart thinking. Also water pollution is much less obvious and visible than a water shortage. People may be drinking polluted water every day and may not become aware of it until it is too late and they are already sick.
I believe that water pollution is more severe than water shortage, because water pollution causes water to be unusable for necessary usage. You could have endless supplies of water, however, if the water is dirty and foul, the water can barely be used. As we read throughout the chapter, our daily use of water can be limited by being careful and taking advantage of using impure water for tasks that do not involve pure water. Polluted water can be toxic and kill many people, but water shortages can be dealt with by smart thinking. Also water pollution is much less obvious and visible than a water shortage. People may be drinking polluted water every day and may not become aware of it until it is too late and they are already sick.
Vocab list
1. matter: anything that occupies space and has mass
2. density: mass of material within a given volume
3. physical properties: properties that can be observed and measured without changing the chemical makeup of the substance
4. freezing point: a physical property that is 0 degrees celsius at normal atmospheric pressure
5. aqueous solution: a water-based solution
6. pure: distilled water
7. mixture: a combination of two or more substances that still hold their individual properties
8. heterogeneous mixture: a composition of substances that are not uniform or the same throughout
9. suspension: a type of mixture in which solid particles are large enough to be filtered and settled out
10. Tyndall effect: the scattering of the light to identify small, solid particles in water
11. colloid: a type of mixture that contains small, solid particles
12. homogeneous mixture: a composition of substances where the substances are mingles together and appear to be uniform
13. solutions: a homogeneous mixture
14. solute: the dissolved substance
15. solvent: the dissolving agent
2. density: mass of material within a given volume
3. physical properties: properties that can be observed and measured without changing the chemical makeup of the substance
4. freezing point: a physical property that is 0 degrees celsius at normal atmospheric pressure
5. aqueous solution: a water-based solution
6. pure: distilled water
7. mixture: a combination of two or more substances that still hold their individual properties
8. heterogeneous mixture: a composition of substances that are not uniform or the same throughout
9. suspension: a type of mixture in which solid particles are large enough to be filtered and settled out
10. Tyndall effect: the scattering of the light to identify small, solid particles in water
11. colloid: a type of mixture that contains small, solid particles
12. homogeneous mixture: a composition of substances where the substances are mingles together and appear to be uniform
13. solutions: a homogeneous mixture
14. solute: the dissolved substance
15. solvent: the dissolving agent
Tuesday, June 14, 2011
A.8 #1-4 p. 22
1. I could do without washing cars, washing windows, and washing pets.
2. I could not do without bathing. Not bathing usually makes one unhealthy, and by not being hygenic, you are making yourself more susceptible to diseases and illnesses.
3. I could reduce water use for bathing, showering, washing hair, washing hands, and watering indoor plants, outdoor plants, and the lawn. I could simply take shorter showers, not fill the bath all the way up to the top, and turn the water off in the sink while scrubbing my hands. I could also not keep the hose on while watering my plants. I could also limit the use of my sprinklers.
4. You could use impure water for washing a car, your windows, and the floor. It can be obtained by using toilet water, the water from a bath, or using water from the washing machine after a load has been cleaned.
2. I could not do without bathing. Not bathing usually makes one unhealthy, and by not being hygenic, you are making yourself more susceptible to diseases and illnesses.
3. I could reduce water use for bathing, showering, washing hair, washing hands, and watering indoor plants, outdoor plants, and the lawn. I could simply take shorter showers, not fill the bath all the way up to the top, and turn the water off in the sink while scrubbing my hands. I could also not keep the hose on while watering my plants. I could also limit the use of my sprinklers.
4. You could use impure water for washing a car, your windows, and the floor. It can be obtained by using toilet water, the water from a bath, or using water from the washing machine after a load has been cleaned.
#3-7, p. 23
3.
a. manufacture of the filter paper: indirect
It is indirect because the water is not intentionally used for the manufacturing of the filter paper. We also can not determine how much water was precisely used. You also do not directly use the water for the end product of the paper.
b. pre-moistening of the sand and gravel: direct
It is direct because the water is obtained and poured into the lab. We intentionally used the water directly for a purpose and we could easily calculate how much was used.
c. use of water to cool the distillation apparatus: direct
It is direct because the water is used specifically for one purpose: to cause the evaporated pure water vapor to condense back into water. We also come into direct contact with it and also can calculate how much we used.
4. Purifying water means to make water pure. This means free of all toxic matters, odorless, free of solid matter, oil, and chemical properties that could be dangerous if consumed. The purest form of water is distilled water.
5. Three techniques that can be done to make water cleaner are oil-water separation, sand filtration, and charcoal adsorption/filtration.
6. In oil-water separation, most of the oil from the surface of the water was removed. In sand filtration, the water came out slightly cleaner, and free of mostly all solid matter except for a few tiny grains of sand. In charcoal adsorption/filtration, the charcoal absorbed the small impurities and almost completely got rid of the odor. The final product after charcoal adsorption/filtration was completely clear.
7. It could not make it suitable for drinking water because the water still had salt. Drinking water for salt could easily make someone sick. This was proven by an electric conductivity test, displaying a lit light bulb resulting from the conductivity of the salt water. A necessary additional step in order to make the water drinkable would be distillation. Distillation evaporates the water in its pure state, leaving all the salt behind.
a. manufacture of the filter paper: indirect
It is indirect because the water is not intentionally used for the manufacturing of the filter paper. We also can not determine how much water was precisely used. You also do not directly use the water for the end product of the paper.
b. pre-moistening of the sand and gravel: direct
It is direct because the water is obtained and poured into the lab. We intentionally used the water directly for a purpose and we could easily calculate how much was used.
c. use of water to cool the distillation apparatus: direct
It is direct because the water is used specifically for one purpose: to cause the evaporated pure water vapor to condense back into water. We also come into direct contact with it and also can calculate how much we used.
4. Purifying water means to make water pure. This means free of all toxic matters, odorless, free of solid matter, oil, and chemical properties that could be dangerous if consumed. The purest form of water is distilled water.
5. Three techniques that can be done to make water cleaner are oil-water separation, sand filtration, and charcoal adsorption/filtration.
6. In oil-water separation, most of the oil from the surface of the water was removed. In sand filtration, the water came out slightly cleaner, and free of mostly all solid matter except for a few tiny grains of sand. In charcoal adsorption/filtration, the charcoal absorbed the small impurities and almost completely got rid of the odor. The final product after charcoal adsorption/filtration was completely clear.
7. It could not make it suitable for drinking water because the water still had salt. Drinking water for salt could easily make someone sick. This was proven by an electric conductivity test, displaying a lit light bulb resulting from the conductivity of the salt water. A necessary additional step in order to make the water drinkable would be distillation. Distillation evaporates the water in its pure state, leaving all the salt behind.
Monday, June 13, 2011
A.5 #1-3 on p. 17
1.
The East: 78% Steam/Electric purposes
The West: 77% Irrigation/agricultural
The South: 63% Steam/Electric
The Midwest: 57% Steam/Electric
Alaska: 55% Mining
Hawaii: 57% Irrigation/agricultural
2. In the East, water is mostly used for Steam/electric purposes and in the West water is mostly used for Irrigation/agriculture. In the East, it is not mostly used for crops because it is not as hot as in the West, and there is more natural rain which keeps the crops thriving without much help from irrigation. In the West, it is the opposite and much assistance is needed so that the plans survive in the hot conditions.
3. In the West it is dry and does not rain as much as it does in the East, Midwest, or the South. In the East, since rain is frequent, water is applied towards more innovative and technological needs such as Steam/Electric. In the Midwest, water is also very commonly used for agriculture as it is for electric because it is in the middle of America, therefore is a mix of the weather.
The East: 78% Steam/Electric purposes
The West: 77% Irrigation/agricultural
The South: 63% Steam/Electric
The Midwest: 57% Steam/Electric
Alaska: 55% Mining
Hawaii: 57% Irrigation/agricultural
2. In the East, water is mostly used for Steam/electric purposes and in the West water is mostly used for Irrigation/agriculture. In the East, it is not mostly used for crops because it is not as hot as in the West, and there is more natural rain which keeps the crops thriving without much help from irrigation. In the West, it is the opposite and much assistance is needed so that the plans survive in the hot conditions.
3. In the West it is dry and does not rain as much as it does in the East, Midwest, or the South. In the East, since rain is frequent, water is applied towards more innovative and technological needs such as Steam/Electric. In the Midwest, water is also very commonly used for agriculture as it is for electric because it is in the middle of America, therefore is a mix of the weather.
ISAS #1, 2, 8-13, 17 on p. 23-24
2. The indirect uses of water that are associated with producing a loaf of bread include packaging the bread (transportation), and creating the mix/dough to bake the bread out of. During packaging, boats and cars are used to deliver breads to and from factories to consumers. This uses water as a form of energy and water is in the recipe to make bread.
8. The amount of water on Earth has most likely changed slightly within the past 100 years because the amount of rain throughout a hundred years has been sporadic and inconsistent. This has especially occurred due to the whole theory of "Global Warming". However, it has changed drastically from the past 1 million years because new oceans and water masses have been formed, and there is much more water on the earth then there was that period of time ago.
9. Oceans, glaciers, rivers, and last is water vapor.
10. This would be true in a situation where the water was not pure. An example of a such a situation would be in a region that can not afford the technology to produce clean water such as Liberia, one of the poorest countries in the world.
11. In the West (California), 77% of water is used for irrigation and agriculture.
12. Glaciers are 2.11% and Lakes are 0.009%
13. It might be possible because water on Earth does not disappear. Instead, it revolves around the hydrologic cycle. The water the dinosaur drank was most likely urinated and then evaporated. After evaporation and condensation, it either reached the ground through rain or snow, and was most likely evaporated many more times. Eventually this water became purified and drinkable for me.
17. Everyone's water use is not calculated exactly and it is difficult to determine how much water each family uses because of indirect water usage. Also, depending on the family's financial resources, some families may directly use water less/more than others.
Quick Blog Question p. 7
Is water purity or water supply more important?
In my opinion, water purity is more important. Droughts rarely last for extended periods of time and the Earth is quickly replenished by rain, snow, melting glaciers etc... If water is not pure, to the extent that it is not even decent enough for human consumption, the supply of water that we do have becomes useless. In order for animals and humans alike to stay healthy, water must be pure enough to drink, wash with, and cook with.
In my opinion, water purity is more important. Droughts rarely last for extended periods of time and the Earth is quickly replenished by rain, snow, melting glaciers etc... If water is not pure, to the extent that it is not even decent enough for human consumption, the supply of water that we do have becomes useless. In order for animals and humans alike to stay healthy, water must be pure enough to drink, wash with, and cook with.
Summer School Chemistry
Hi readers,Welcome to my blog! My name is Eva and I am studying Chemistry and will be posting blogposts related and about this subject. I hope you found my posts informative, descriptive, and in depth.
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