Question 1

A weather balloon is released at sea level where the atmospheric pressure is 1.00 atm and the temperature is 20°C. As the balloon rises, the external pressure drops to 0.60 atm and the temperature drops to -10°C. Assuming the amount of gas in the balloon remains constant, which of the following best describes what happens to the volume of the balloon?
Correct answer: The volume increases because the decrease in pressure has a greater effect than the decrease in temperature.

Accepted Answer

The volume increases because the decrease in pressure has a greater effect than the decrease in temperature.

Question 2

Which of the following is the correct conversion for a pressure of 2.50 atm to pascals (Pa)?
Correct answer: 2.50 atm × 101325 Pa/atm = 253,312.5 Pa

Accepted Answer

2.50 atm × 101325 Pa/atm = 253,312.5 Pa

Question 3

A scuba diver's tank contains 12.0 L of air at a pressure of 200 atm and a temperature of 27°C. If the diver releases air until the pressure drops to 1.00 atm at the same temperature, what volume would this air occupy at 1.00 atm?
Correct answer: 2,400 L

Accepted Answer

2,400 L

Question 4

Which of the following statements best explains why atmospheric pressure decreases with increasing altitude?
Correct answer: There are fewer gas molecules per unit volume at higher altitudes, resulting in fewer collisions with surfaces.

Accepted Answer

There are fewer gas molecules per unit volume at higher altitudes, resulting in fewer collisions with surfaces.

Question 5

A sample of gas occupies 4.00 L at 1.00 atm and 300 K. If the pressure is increased to 2.00 atm and the temperature is raised to 400 K, what is the new volume of the gas?
Correct answer: 2.67 L

Accepted Answer

2.67 L

Question 6

A patient is administered oxygen from a tank at 150 atm and 10.0 L. If the oxygen is released at 1.00 atm and 25°C, what volume will the oxygen occupy at these conditions? (Assume temperature is constant.)
Correct answer: 1,500 L

Accepted Answer

1,500 L

Question 7

Which of the following best describes the relationship between the number of moles of gas and the volume it occupies at constant temperature and pressure?
Correct answer: The volume is directly proportional to the number of moles.

Accepted Answer

The volume is directly proportional to the number of moles.

Question 8

A 5.00 g sample of helium gas is placed in a 10.0 L container at 27°C. What is the pressure inside the container? (R = 0.0821 L·atm/(mol·K); He molar mass = 4.00 g/mol)
Correct answer: 3.12 atm

Accepted Answer

3.12 atm

Question 9

A gas sample is collected over water at 25°C and a total pressure of 755 mm Hg. The vapor pressure of water at 25°C is 23.8 mm Hg. What is the partial pressure of the dry gas?
Correct answer: 731.2 mm Hg

Accepted Answer

731.2 mm Hg

Question 10

Which of the following best describes the function of a barometer?
Correct answer: It measures atmospheric pressure by balancing the weight of a column of mercury against the pressure exerted by the atmosphere.

Accepted Answer

It measures atmospheric pressure by balancing the weight of a column of mercury against the pressure exerted by the atmosphere.

Question 11

A 2.00 L container holds nitrogen gas at 3.00 atm and 27°C. If the gas is compressed to 1.00 L and heated to 327°C, what is the final pressure?
Correct answer: 18.0 atm

Accepted Answer

18.0 atm

Question 12

Which of the following is NOT a correct unit conversion for pressure?
Correct answer: 1 atm = 1000 torr

Accepted Answer

1 atm = 1000 torr

Question 13

A gas occupies 500 mL at 25°C and 1.00 atm. What will be its volume at 100°C and 1.00 atm?
Correct answer: 646 mL

Accepted Answer

646 mL

Question 14

A tire is inflated to a pressure of 32.0 psi at 20°C. On a hot day, the temperature inside the tire rises to 50°C. Assuming the volume remains constant, what is the new pressure in psi?
Correct answer: 35.3 psi

Accepted Answer

35.3 psi

Question 15

Which of the following scenarios best illustrates Boyle's Law?
Correct answer: A syringe plunger is pushed in, decreasing the volume and increasing the pressure of the trapped air.

Accepted Answer

A syringe plunger is pushed in, decreasing the volume and increasing the pressure of the trapped air.

Question 16

A 1.00 mol sample of an ideal gas is at 1.00 atm and 273 K. What is its volume?
Correct answer: 22.4 L

Accepted Answer

22.4 L

Question 17

A gas cylinder contains 0.500 mol of oxygen at 2.00 atm and 300 K. If another 0.500 mol of oxygen is added at constant volume and temperature, what is the new pressure?
Correct answer: 4.00 atm

Accepted Answer

4.00 atm

Question 18

Which of the following is a key assumption of the ideal gas law that may not hold true at very high pressures or very low temperatures?
Correct answer: Gas molecules do not attract or repel each other.

Accepted Answer

Gas molecules do not attract or repel each other.

Question 19

A hospital stores oxygen at 3000 psi in a 50.0 L tank. If the oxygen is released to fill a 500 L chamber at 1.00 atm and 25°C, what is the approximate final pressure in the chamber? (1 atm = 14.7 psi; assume temperature is constant)
Correct answer: 8.2 atm

Accepted Answer

8.2 atm

Key Concepts of Gases and Gas Laws

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