Chemistry Test Gas Laws 3

Question 1

A gas at 1.5 atm and 10.0 L is compressed to 5.0 L at constant temperature. What is the new pressure?

Accepted Answer

3.0 atm

Answer

Boyle's Law: P2 = P1V1/V2 = (1.5 × 10.0)/5.0 = 3.0 atm.

Question 2

Which of the following best describes an ideal gas?

Accepted Answer

Point masses with no intermolecular forces

Answer

An ideal gas is modeled as point masses (negligible volume) with no intermolecular forces.

Question 3

At constant temperature and pressure, which gas sample contains the most molecules?

Accepted Answer

All samples contain the same number

Answer

Avogadro's Law states equal volumes of gases at the same T and P contain equal numbers of molecules.

Question 4

A gas exerts 2.0 atm in a 3.0 L container. If the container is expanded to 6.0 L at constant temperature, what is the new pressure?

Accepted Answer

1.0 atm

Answer

Boyle's Law: P2 = (2.0 × 3.0)/6.0 = 1.0 atm.

Question 5

What happens to the average kinetic energy of gas molecules when temperature increases?

Accepted Answer

Increases

Answer

Average kinetic energy is directly proportional to absolute temperature: KE = (3/2)kT.

Chemistry Practice Test