Expt. 11
Phase Changes

Purpose: To examine the states of matter of H2O under changes in temperature and pressure.

Data: | Pressure (atm) | Temperature(degrees Celsius) | Gas Volume(L) | Liquid Volume(L) | Ice Volume(L) | Heat change | Room Temperature | 1.000 | 20.00 | 0.000 | .1470 | 0.000 | 0.000 | 4 atm. | 1.000 | 200.0 | 317.6 | 0.000 | 0.000 | 0.000 | .5 atm | .5000 | 150.0 | 566.7 | 0.000 | 0.000 | 412.0 | Lowest atm found | 0.004 | -20.00 | 0.000 | 0.000 | .1600 | -144.8 |

Questions:
1. At what temperature does the water begin to boil and start turning into vapor?
100 degrees Celsius.

2. At the boiling point when you have a mixture of liquid and vapor and you are applying heat, does the temperature change?
No.

3. After all of the liquid has boiled off and turned into vapor, does the temperature increase?
Yes.

4. How does the vapor volume compare with the original amount of liquid volume you had when you started the experiment?
Vapor volume increased as the liquid volume decreased until the liquid volume reached zero liters.

5. At what temperature does the vapor start condensing into liquid?
144.83 degrees Celsius.

6. How does the volume of water you have now ( at room temperature) compare with the volume of water you started out with?
Same volume of .147 liters.

7. While the water is freezing does the temperature continue to deop?
Yes.

8. Is the ice volume higher or lower than the original volume of water?
The ice volume is higher.

9. Why are they different?
Ideal gas law states an increase in pressure yields a higher temperature.

10. At what temperature does the ice begin to melt?
.003 degrees Celsius.

11. Is it the same as the freezing point when the pressure was 4 atm?
No.

12. At what temperature does the water begin to boil?
81.663 degrees Celsius.

13. Is it the same as the boiling