factors affecting solubility[1]

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Beijing World Youth Academy
Candidate number: 000791 011
YeiYoung Choo
Experiment No ____
2.0 hours
D1=2,D2=1,D3=0
The Effect of Temperature on the Solubility of
Carbon Dioxide in Water under Constant
Pressure
Beijing World Youth Academy
Subject: Chemistry
Student name: YeiYoung Choo
Candidate number: 000791 011
January 21, 2009
Teacher Helen Xu
Beijing World Youth Academy
Candidate number: 000791 011
YeiYoung Choo
The Effect of Temperature on the Solubility of Carbon Dioxide in
Water under Constant Pressure
(Evaluated for Design)
Research Question
What is the effect of temperature on the solubility of carbon dioxide gas in de-ionised
water under constant pressure?
Introduction
Temperature is known as one of the factors that affect the solubility of a gas in
its solvent. Because the enthalpy of solution for gases dissolved in waters is usually
negative (Reger, 2009; 482), students may hypothesize that the increase in the
temperature will decrease the solubility of carbon dioxide in water and the decrease in
the temperature will increase the solubility of carbon dioxide in water. In this
experiment, the solubility of carbon dioxide in the water of selected temperatures—0°C,
20°C, 40°C and 60°C—will be tested by using the carbon dioxide gas prepared from the
reaction between calcium carbonate and hydrochloric acid and dissolving it in deionised water within a gas syringe.
In regards to the temperature, the gas will not be heated directly but the
temperature will be manipulated according to the temperature of the solvent, which is
de-ionised water. The temperature gas will be affected when thoroughly shaking the deionised water of a selected temperature with it in the gas syringe and also when putting
the gas syringe into the beaker in which there would be heat transfer through the wall of
the barrel (which is made of glass). As for pressure, even though the pressure will not be
measured to keep constant in the experiment, it will be kept controlled for each trial of
dissolving carbon dioxide by filling the same amount of gas in a gas syringe and filling
in the same amount of de-ionised water in addition.
Beijing World Youth Academy
Candidate number: 000791 011
YeiYoung Choo
Variables
Independent variable
Temperature under which carbon dioxide Manipulating the temperature of the dewill be dissolved in water
ionised water by heating or cooling to
produce de-ionised waters of selected
temperatures: 0°C, 20°C, 40°C, 60°C
Dependent variable
Solubility of carbon dioxide in water
Dissolve carbon dioxide in water within a
gas syringe by shaking and measure the
volume of undissolved carbon dioxide by
pressing the plunger
Controlled variables
How to control
Characteristic/Nature of the solvent (water) Using de-ionised water for every trial of
dissolving carbon dioxide in it
Temperature under which carbon dioxide All gas syringes filled with carbon
gas is kept before dissolving in water
dioxide left under room temperature
Pressure under which carbon dioxide is 30mL of carbon dioxide gas thoroughly
dissolved in water
shaken with 20mL of water within a
60mL gas syringe for every trial
Volume of water used to dissolve carbon 20mL for every trial
dioxide in the gas syringe
Condition of preparing carbon dioxide
Carbon dioxide gas produced by reacting
calcium carbonate with hydrochloric acid
under room temperature
Beijing World Youth Academy
Candidate number: 000791 011
YeiYoung Choo
Materials required
Chemical
1M Hydrochloric acid
(De-ionised water)1
Calcium carbonate / Marble chips
Material
Digital scale
Conical flask
Graduated beaker
Bung (with a hole through which a glass
tube is inserted)
Rubber stopper
Rubber tube (Long; approximately 30cm)
Rubber tube (Short: approximately 5cm)
Funnel
Clamp&Stand
Pinch clamp
Alcohol lamp
Gauze heat-proof mesh
Tripod stand
Glass rod
Beaker tong
Container
Ice
Glass gas syringe
Thermometer
Safety material
Safety glasses2
Neoprene gloves3
Quantity
1
1
5
1
Uncertainty
±0.01g
25ml; 150ml; ±25ml
1
2
1
1
1
1
1
1
1
1
1
1
13
1
60mL±1mL
±1°C
Quantity
1
1
Method
Part (a) Preparing Gas Syringes Filled with Carbon Dioxide
1
Determining the solubility of gas requires purification of the liquid solvent and thorough degassing of
the solvent. Hefter, G.. T. and Reginald P. T. Tomkins, The Experimental Determination of Solubilities. ed
3 (New York: John Wiley and Sons, 2003), 102.
2
Must wear safety glasses because hydrochloric acid is toxic and corrosive. Oxford University.
“Chemical
Safety
Data:
Hydrochloric
Acid.”
Dr
Hugh
Cartwright
-
Hands-on
Science.
http://cartwright.chem.ox.ac.uk/hsci/chemicals/hydrochloric_acid.html (accessed January 30, 2010).
3
Helpful to wear safety gloves even though the concentration is not too high. Oxford University,
“Chemical Safety Data: Hydrochloric Acid.” Dr Hugh Cartwright - Hands-on Science,
http://cartwright.chem.ox.ac.uk/hsci/chemicals/hydrochloric_acid.html (accessed January 30, 2010).
Beijing World Youth Academy
Candidate number: 000791 011
YeiYoung Choo
1. Weigh 10g of marble chips (calcium carbonate) on a digital scale.
2. Put the marble chips into the conical flask
3. Seal the flask with a bung (with a glass tube inserted in the middle) and set up the
apparatus for gas collection as shown below:
Figure 1. Diagrammic representation of how the apparatus should be set up to collect
carbon dioxide gas, produced from a reaction between hydrochloric acid and calcium
carbonate, in a gas syringe
funnel
rubber tube
1M hydrochloric acid
pinch clamp
glass tube
stoppered conical flask
calcium carbonate
gas syringe*
*Make sure the plunger of the gas syringe is pushed inward to maximum.
4. Open the pinch clamp and let the 1M hydrochloric acid flow down into the conical
flask containing marble chips.
5. Leave the pinch clamp open until almost all hydrochloric acid flows down.
6. Close the clamp when there is very small amount of hydrochloric acid left in the
funnel but enough to prevent any gas entering.
7. Pour more hydrochloric acid to the funnel.
8. Repeat steps 4. to 7. to continue collecting the gas produced by the reaction between
calcium carbonate and hydrochloric acid, until 45mL of gas is filled in the gas syringe,
as indicated by to what number on the gas syringe the plunger has been pushed outward.
9. Pull out the gas syringe from the rubber tube and, with the syringe still headed
upward, push the plunger up until the volume of gas in it reaches 30mL, and quickly
seal with a rubber stopper.
10. Get another gas syringe with its plunger pushed inward to maximum.
11. Hold the conical flask and move slightly to mingle the marble chips, so as to make
sure more of the unreacted marble chips are exposed for the next reaction with
Beijing World Youth Academy
Candidate number: 000791 011
YeiYoung Choo
hydrochloric acid.
12. Place the conical flask back to its position as shown previously in figure 1.
13. Repeat steps 4. to 9.
14. Repeat steps 10. to 13. to fill one more gas syringe so that three gas syringes
containing the same gas are prepared.
15. Repeat steps 1. to 14. to produce ten more gas syringes filled with gas.
Part (b) Dissolving carbon dioxide in de-ionised water of 20°C
16. Fill 100mL of de-ionised water in a graduated beaker.
17. Check the temperature of the water with a thermometer inserted in it and if it is
higher than 20°C, holding the beaker tilted, run cold tap water along the surface of the
beaker to reach 20±1°C on the thermometer.
18. Get one of the gas syringes prepared in Part (a) and hold it inversely, very close to
the de-ionised water in the beaker.
19. Remove the rubber stopper and immediately carry out the next step, as shown below
in figure 2.
20. Put the mouth of the gas syringe into the water and pull the plunger to fill the 20mL
of water so that the end of the plunger reads 60mL on the graduation of the gas syringe.
Figure 2. Diagrammic representation of how the gas syringe should be placed in the
beaker containing de-ionised water to fill it with 20mL of water in addition to the 30mL
of gas already filled in.
pull
gas syringe
carbon dioxide gas
de-ionised water being filled in
de-ionised water
21. Pull the gas syringe out of the beaker, stopper it again and shake thoroughly to make
the gas dissolve in water.
22. Pushing the stopper to make sure it is firmly attached to the mouth of the syringe,
press the plunger inward.
Beijing World Youth Academy
Candidate number: 000791 011
YeiYoung Choo
23. Push until the plunger does not go further inward.
24. See where the end of the plunger has reached in the gas cylinder.
25. Repeat steps 17. to 24. two more times to produce three data for the de-ionised
water of (about) 20°C.
Part (c) Dissolving carbon dioxide in de-ionised water of 40°C
26. Fill in a graduated beaker with 100mL of de-ionised water.
27. Heat the water to 40°C with an alcohol lamp by setting up the apparatus as shown in
figure 3 below:
Figure 3. Diagrammic representation of how the apparatus should be set up to heat the
de-ionized water, in which carbon dioxide gas would be dissolved afterwards in a gas
syringe, to a selected temperature with the aid of temperature measurement by
thermometer
thermometer
graduated beaker
De-ionised water
gauze heat-proof mesh
tripod stand
alcohol lamp
28. Stir the de-ionised water with a glass rod often during the heating process.
29. When the thermometer reads 40°C, carry the beaker out of the heating apparatus
with a beaker tong.
30. Same as carried out in Part (b), repeat steps 18. to 24. to dissolve the gas in the
syringe in the heated de-ionised water.
31. Check the thermometer and if the temperature has gone down, place the beaker back
on the tripod stand using a beaker tong and heat up to 40°C.
32. Repeat steps 29. to 30. to produce another reading for dissolving carbon dioxide in
the heated water.
33. Check the thermometer again as done in step 31. and repeat steps 29. to 30. to
produce the third reading.
Part (d) Dissolving carbon dioxide in de-ionised water of 60°C
Beijing World Youth Academy
Candidate number: 000791 011
YeiYoung Choo
34. Fill in a graduated beaker with 100mL of de-ionised water.
35. Heat the water to 60°C with an alcohol lamp by setting up the apparatus as shown in
figure 3 in Part (c).
36. When the thermometer reads 60°C, carry the beaker out of the heating apparatus
with a beaker tong.
37. Same as carried out in Part (b), repeat steps 18. to 24. to dissolve the gas in the
syringe in the heated de-ionised water.
38. Check the thermometer and if the temperature has gone down, place the beaker back
on the tripod stand using a beaker tong and heat up to 60°C.
39. Repeat steps 36. to 37. to produce another reading for dissolving carbon dioxide in
the heated water.
40. Check the thermometer again as done in step 38, and repeat steps 36. to 37. to
produce the third reading.
Part (e) Dissolving carbon dioxide in de-ionised water of 0°C
41. Fill in a graduated beaker with 100mL of de-ionised water.
42. Fill in about 3/4 of a container with tap water and put ice as shown below in figure 4.
43. Place a thermometer in the beaker from step 41. and place the beaker in the
container to cool down the de-ionised water, as shown below in figure 4.
Figure 4. Diagrammic representation of preparing de-ionised water of 0°C
thermometer
graduated beaker
de-ionised water
ice
container
44. Check the thermometer and wait until the temperature goes down to 0°C.
45. If the temperature stops decreasing, put some more ice in the container.
46. During the process of cooling down the de-ionised water, stir it with a stirring rod
often.
47. When the thermometer reads 0°C, carry the beaker out of the container using a
beaker tong.
48. Same as carried out in Part (b), repeat steps 18. to 24. to dissolve the gas in the
syringe in the de-ionised water.
49. Check the thermometer and if the temperature has increased, place the beaker back
Beijing World Youth Academy
Candidate number: 000791 011
YeiYoung Choo
into the container.
50. Take out the graduated beaker the thermometer reads 0°C.
51. Repeat steps 48. to produce another reading for dissolving carbon dioxide in the deionised water.
52. Repeat step 49. to 51. to produce the third reading.
Part (f) Measuring the mass of carbon dioxide
53. Notice that there is one gas syringe from part (a) left unused.
54. Measure the mass of the gas syringe with its stopper on a digital balance as shown
below in figure 5.
Figure 5. Digrammic representation of measuring the mass [g] the gas syringe filled
with carbon dioxide gas produced by the reaction between calcium carbonate and
hydrochloric acid
gas syringe
carbon dioxide gas
stopper
digital balance
55. Remove the stopper and push the plunger the inward to get rid of carbon dioxide gas
within the gas syringe.
56. Weigh the empty gas syringe and the stopper together on the digital balance.
Bibliography
Hefter, G.. T. and Reginald P. T. Tomkins, The Experimental Determination of
Solubilities. ed 3. New York: John Wiley and Sons, 2003.
Beijing World Youth Academy
Candidate number: 000791 011
YeiYoung Choo
Oxford University. “Chemical Safety Data: Hydrochloric Acid.” Dr Hugh Cartwright Hands-on
Science.
http://cartwright.chem.ox.ac.uk/hsci/chemicals/hydrochloric_acid.html
(accessed
January 30, 2010).
Reger, Daneil L., Scott R. Goode, and David W. Ball. Chemistry: Principles and
Practice. New York: Cengage Learning, 2009.
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