Unit 3: Gases

11. The ideal gas law is represented by which of the following equations?

a) PV = nRT
b) PV = mRT
c) P = nRT/V
d) V = nRT/P
Answer: a) PV = nRT

12. Which of the following assumptions is part of the kinetic molecular theory of gases?

a) Gas molecules are in constant, random motion
b) Gas molecules attract each other strongly
c) The volume of gas molecules is significant compared to the container
d) Gas molecules move in a fixed, orderly pattern
Answer: a) Gas molecules are in constant, random motion

13. According to Boyle’s law, the pressure of a gas is inversely proportional to its volume when:

a) Temperature and amount of gas are constant
b) Temperature and pressure are constant
c) Volume and amount of gas are constant
d) Temperature and volume are constant
Answer: a) Temperature and amount of gas are constant

14. Charles’s law states that the volume of a gas is directly proportional to its temperature when:

a) Pressure and amount of gas are constant
b) Pressure and volume are constant
c) Volume and amount of gas are constant
d) Temperature and pressure are constant
Answer: a) Pressure and amount of gas are constant

15. The gas law that combines Boyle’s, Charles’s, and Gay-Lussac’s laws is:

a) Ideal gas law
b) Dalton’s law
c) Graham’s law
d) Avogadro’s law
Answer: a) Ideal gas law

16. According to Avogadro’s law, the volume of a gas is directly proportional to:

a) The temperature of the gas
b) The pressure of the gas
c) The number of moles of the gas
d) The density of the gas
Answer: c) The number of moles of the gas

17. The constant “R” in the ideal gas law equation represents:

a) The universal gas constant
b) The gas constant specific to the gas
c) The rate of reaction
d) The molar mass of the gas
Answer: a) The universal gas constant

18. The pressure exerted by a gas in a container is due to:

a) The weight of the gas
b) The collisions of gas molecules with the container walls
c) The volume of the gas
d) The temperature of the gas
Answer: b) The collisions of gas molecules with the container walls

19. Dalton’s law of partial pressures states that:

a) The total pressure of a gas mixture is the sum of the partial pressures of each gas
b) The pressure of each gas in a mixture is equal
c) The pressure of a gas is inversely proportional to its temperature
d) The partial pressure of a gas is proportional to its volume
Answer: a) The total pressure of a gas mixture is the sum of the partial pressures of each gas

20. What is the standard temperature and pressure (STP) for gases?

a) 0°C and 1 atm
b) 25°C and 1 atm
c) 0°C and 760 mmHg
d) 25°C and 760 mmHg
Answer: a) 0°C and 1 atm