Unit 2: #8-14

Question 1

8a. What is the relationship between gas pressure and volume?

Answer 1

As volume decreases, pressure increases because there will be more collisions in a smaller space.

Question 2

8b. What is the relationship between gas pressure and Celsius temperature?

Answer 2

As temperature increases, pressure increases because more motion equals more collisions, but pressure does not equal 0 at 0 degrees Celsius.

Question 3

8c. What is the relationship between gas pressure and Kelvin temperature?

Answer 3

As temperature increases, pressure increases because more motion equals more collisions, and 0 degrees Kelvin means 0 pressure because it’s so cold, theres no motion.

Question 4

9. A sample of carbon dioxide has a volume of 2.0L at a temperature of 10°C. What volume will the sample have when the temperature is increased to 110°C? Use a IFE table.

Answer 4

…..P……..V………T……..N
I…./……2.0L….283K…/
F…/……..?……..383K…/
E…/……^T……….^……./

2.0L x 383K/283K = 2.7L

Question 5

10. A 12.7L sample of gas is under a pressure of 740 mmHg at 20°C. What will be the volume of the gas if the pressure increases to 1.00atm and the temperature drops to 0.0°C. Use an IFE table.

Answer 5

…….P…….V……….T……….N.
I…740…12.7….293……./
F..760……?…….273……./
E….^…V P, V T….V……../

12.7L x 740mmHg/760mmHg x 273K/293K = 12L

Question 6

11a. Determine the pressure in the following flask. Proom: 733mmHg, 95 against 41 (95 to Proom)

Answer 6

733mmHg + 54mmHg = 787mmHg

Question 7

11b. Determine the pressure in the following flask. Proom: 733mmHg, 104 to 31 (31 to Proom)

Answer 7

733mmHg - 73mmHg = 660mmHg

Question 8

12. Explain why the alcohol level in a thermometer rises when it is placed in a warmer fluid.

Answer 8

1. Warmer, faster, particles collide with glass particles of the thermometer and transfer their energy.
2. Faster, glass particles collide with alcohol particles and transfer their energy.
3. Alcohol particles’ collisions with each other are more energized, so they are spread out.

Question 9

13. Describe what happens at the particle level when a glass of hot chocolate cools down to room temperature.

Answer 9

1. Warmer hot chocolate particles collide with cooler air particles and their energy is transferred out to the air.
2. Less energetic, “hot” chocolate particles are slower and get closer together.

Question 10

14. Describe the “accounts” in which energy can be stored in substances, and how that energy impacts the particles in the substance.

Answer 10

Eth (thermal): related to particle motion
Eph (phase): related to particle spacing