At STP: pressure = 1 atm = 700 mmHg, 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.
Question 1A 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?
Question 2What is the density (in g/L) of a gas with a molar mass of 60 g/mol at 0.75 atm and 27 °C?
Question 3A 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?
Question 44 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 isothermically to 36.0 L, what would be the final pressure?
Question 5A 9.0 L volume of chlorine gas is heated from 27 °C to 127 °C at constant pressure. What is the final volume?
Question 6The 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?
Question 7A 0.614 mole sample of ideal gas at 12 °C occupies a volume of 4.3 L. What is the pressure of the gas?
Question 8Helium 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?
Question 9What is the average velocity of nitrogen gas molecules at STP?
Molar mass of nitrogen = 14 g/mol
Question 10A 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?
Answers1. 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