Gas Laws Quiz
Questions: 16 · 10 minutes
1. Under which conditions does Charles’s law state that gas volume is directly proportional to absolute temperature?
Constant pressure and constant amount of gas
Constant volume and constant amount of gas
Constant temperature and constant amount of gas
Constant pressure and constant volume
2. A sealed aerosol can is left in a hot environment. Assuming its volume stays nearly constant, why does its internal pressure rise?
Heating creates additional gas molecules inside the sealed can.
Heating causes the gas molecules to lose kinetic energy.
The gas contracts and leaves more empty space in the can.
Faster-moving molecules collide with the container walls more forcefully and frequently.
3. A gas is collected over water at a total pressure of 755 torr. If water vapor contributes 24 torr, what is the pressure of the dry gas?
779 torr
755 torr
731 torr
31.5 torr
4. Why must Kelvin temperatures be used in proportional gas-law calculations?
Kelvin units make pressure and volume use the same numerical scale.
Celsius values are valid only when pressure is measured in torr.
Kelvin automatically corrects for non-ideal gas behavior.
Kelvin is an absolute scale, so temperature ratios represent thermal changes correctly.
5. At the same temperature, approximately how many times faster does helium gas effuse than neon gas? Use molar masses of 4.00 g/mol for helium and 20.18 g/mol for neon.
1.12 times faster
2.25 times faster
5.05 times faster
25.5 times faster
6. Which statement correctly describes Boyle’s law for a fixed amount of gas at constant temperature?
Pressure and volume are inversely proportional.
Pressure and volume are directly proportional.
Volume is directly proportional to temperature in degrees Celsius.
Pressure is directly proportional to the number of moles only.
7. A sealed, rigid container holds a fixed amount of gas. Which law relates its pressure directly to its absolute temperature?
Boyle’s law
Gay-Lussac’s law
Avogadro’s law
Graham’s law
8. Using PV = nRT and R = 0.08206 L·atm/(mol·K), approximately how many moles are in a 5.00 L container at 0.984 atm and 300 K?
0.050 mol
0.120 mol
0.500 mol
0.200 mol
9. A gas occupies 3.0 L at 1.2 atm. If it is compressed to 2.0 L at constant temperature, what is its new pressure?
1.8 atm
0.80 atm
2.4 atm
3.2 atm
10. A gas mixture has a total pressure of 760 torr. Oxygen contributes 160 torr and nitrogen contributes 590 torr. What is the partial pressure of the remaining gas?
600 torr
170 torr
10 torr
750 torr
11. Why do real gases tend to deviate most from ideal behavior at high pressure and low temperature?
Molecular volume and intermolecular attractions become more significant.
Their particles stop moving entirely under those conditions.
Their molar masses decrease as pressure rises.
The Kelvin scale no longer measures temperature accurately.
12. According to Avogadro’s law, what happens at constant temperature and pressure when the amount of gas increases?
The volume decreases in inverse proportion to the amount.
The pressure increases while volume remains fixed.
The volume increases in direct proportion to the amount.
The absolute temperature decreases.
13. At the same temperature and pressure, which gas would have the greatest density?
CH₄
CO₂
O₂
N₂
14. A gas is held beneath a freely moving piston at constant external pressure. If its Kelvin temperature doubles while the amount of gas stays fixed, what happens to its volume?
It decreases to one-half of its original value.
It stays unchanged because pressure is constant.
It doubles.
It increases by a factor of four.
15. A gas occupies 2.0 L at 1.0 atm and 300 K. It changes to 1.5 L and 450 K. Using the combined gas law, what is the final pressure?
0.50 atm
2.0 atm
1.3 atm
3.0 atm
16. At constant pressure, a gas occupies 2.5 L at 300 K. What volume will it occupy at 360 K?
2.1 L
4.5 L
3.6 L
3.0 L