Ideal Gas Law Test Questions

Ideal Gas Law Chemistry Test Questions and Answers

The ideal gas law is an important concept in chemistry. It can be used to predict the behavior of real gases in situations other than low temperatures or high pressures. This collection of ten chemistry test questions deals with the concepts introduced with the ideal gas laws.

Useful information:
At STP: pressure = 1 atm = 700 mm Hg, temperature = 0 °C = 273 K
At STP: 1 mole of gas occupies 22.4 L

R = ideal gas constant = 0.0821 L·atm/mol·K = 8.3145 J/mol·K

Answers appear at the end of the test.

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Question 1

At low temperatures, real gases behave like ideal gases.
At low temperatures, real gases behave like ideal gases. Paul Taylor, Getty Images
A balloon contains 4 moles of an ideal gas with a volume of 5.0 L.
If an additional 8 moles of the gas is added at constant pressure and temperature, what will be the final volume of the balloon?
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Question 2

What is the density (in g/L) of a gas with a molar mass of 60 g/mol at 0.75 atm and 27 °C?
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Question 3

A mixture of helium and neon gases is held in a container at 1.2 atmospheres. If the mixture contains twice as many helium atoms as neon atoms, what is the partial pressure of helium?
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Question 4

4 moles of nitrogen gas are confined to a 6.0 L vessel at 177 °C and 12.0 atm. If the vessel is allowed to expand isothermally to 36.0 L, what would be the final pressure?
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Question 5

A 9.0 L volume of chlorine gas is heated from 27 °C to 127 °C at constant pressure. What is the final volume?

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Question 6

The temperature of a sample of an ideal gas in a sealed 5.0 L container is raised from 27 °C to 77 °C. If the initial pressure of the gas was 3.0 atm, what is the final pressure?

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Question 7

A 0.614 mole sample of ideal gas at 12 °C occupies a volume of 4.3 L. What is the pressure of the gas?
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Question 8

Helium gas has a molar mass of 2 g/mol. Oxygen gas has a molar mass of 32 g/mol.
How much faster or slower would oxygen effuse from a small opening than helium?
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Question 9

What is the average velocity of nitrogen gas molecules at STP?
Molar mass of nitrogen = 14 g/mol

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Question 10

A 60.0 L tank of chlorine gas at 27 °C and 125 atm springs a leak. When the leak was discovered, the pressure was reduced to 50 atm. How many moles of chlorine gas escaped?
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1. 15 L
2. 1.83 g/L
3. 0.8 atm
4. 2.0 atm
5. 12.0 L
6. 3.5 atm
7. 3.3 atm
8. Oxygen would effuse 1/4 as fast as helium (rO = 0.25 rHe)
9. 493.15 m/s
10. 187.5 moles