# Gas Laws Practice Questions II with Answers

1. It is found that 250. mL of a gas at STP has a mass of 0.700 g. What is the molar mass?
• A) 62.7 g/mol
• B) 2.80 g/mol
• C) 15.9 g/mol
• D) 11.2 g/mol
• E) 128 g/mol
1. What volume does 40.5 g of N2 occupy at STP?
• A) 64.8 L
• B) 1.81 L
• C) 32.4 L
• D) 50.7 L
• E) none of the above
1. Body temperature is about 309 K. On a cold day, what volume of air at 276 K must a person with a lung capacity of 2.2 L breathe in to fill the lungs?
• A) 2.46 L
• B) 1.97 L
• C) 2.08 L
• D) 3.93 L
• E) none of the above
1. Air has an average molar mass of 29.0 g/mol. The density of air at 0.97 atm and 30.0°C is:
• A) 29.0 g/L
• B) 39.0 g/mL
• C) 1.13 g/L
• D) 1.35 g/mL
• E) 11.4 g/L
1. If a 17.90-g sample of a gas occupies 10.0 L at STP, what is the molar mass of the gas at 125°C?
• A) 5.48 g/mol
• B) 40.1 g/mol
• C) 18.4 g/mol
• D) 58.5 g/mol
• E) Not enough information is given.
1. What volume of measured at STP is produced by the combustion of 6.27 g of natural gas according to the following equation?
• A) 8.76 L
• B) 17.5 L
• C) 4.38 L
• D) 19.1 L
• E) 3.14 L
1. A chemical reaction produced 10.1 cm3 of nitrogen gas at 23 °C and 746 mmHg. What is the volume of this gas if the temperature and pressure are changed to 0 °C and 760 mmHg?
• A) 9.14 cm3
• B) 9.49 cm3
• C) 10.8 cm3
• D) 11.2 cm3
• E) 10.1 cm3
1. A sample of gas occupies 20.0 liters at 32 °C when the pressure is 0.750 atm. What temperature in °C is required to increase the volume to 25.0 liters at a pressure of 0.680 atm?
• A) -3.90 °C
• B) 309 °C
• C) 72.7 °C
• D) 346 °C
• E) 36.1 °C
1. Which of the following is not being considered as an energy source for the future?
• A) ethanol
• B) methanol
• C) seed oil
• D) shale oil
• E) carbon dioxide
1. One of the main advantages of hydrogen as a fuel is that:
• A) The only product of hydrogen combustion is water.
• B) It exists as a free gas.
• C) It can be economically supplied by the world’s oceans.
• D) Plants can economically produce the hydrogen needed.
• E) It contains a large amount of energy per unit volume of hydrogen gas.
1. Which of the following is both a greenhouse gas and a fuel?
• A) carbon dioxide
• B) coal
• C) freon
• D) methane
• E) nitrogen
1. All of the following statements about the greenhouse effect are true except:
• A) It occurs only on earth.
• B) The molecules H2O and CO2 play an important role in retaining the atmosphere’s heat.
• C) Low humidity allows efficient radiation of heat back into space.
• D) The carbon dioxide content of the atmosphere is quite stable.
• E) A and D
1. This fossil fuel was formed from the remains of plants that were buried and exposed to high pressure and heat over time.
• A) coal
• B) natural gas
• C) diesel fuel
• D) propane
• E) Gasoline
1. Consider a sample of gas in a container on a comfortable spring day. The Celsius temperature suddenly doubles, and you transfer the gas to a container with twice the volume of the first container. If the original pressure was 12 atm, what is a good estimate for the new pressure?
• A) 3 atm
• B) 5.5 atm
• C) 6.4 atm
• D) 12 atm
• E) 15 atm
1. Which of the following is the best qualitative graph of P versus molar mass of a 1-g sample of different gases at constant volume and temperature?
• A)
• B)
• C)
• D)
• E) none of the above
1. A 140.0-g sample of water at 25.0°C is mixed with 111.7 g of a certain metal at 100.0°C. After thermal equilibrium is established, the (final) temperature of the mixture is 29.6°C. What is the specific heat capacity of the metal, assuming it is constant over the temperature range concerned?
• A) 0.34 J/g°C
• B) 0.68 J/g°C
• C) 0.22 J/g°C
• D) 2.9 J/g°C
• E) none of the above
1. When 0.72 g of a liquid is vaporized at 110°C and 0.967 atm, the gas occupies a volume of 0.559 L. The empirical formula of the gas is CH2. What is the molecular formula of the gas?
• A) CH2
• B) C2H4
• C) C3H6
• D) C4H8
• E) none of the above