Question: A helium balloon initially at room temperature is dunked into liquid nitrogen (T = 77 K). Which of the following will occur?

Answer Options: A The balloon bursts immediately. B The balloon shrinks dramatically in volume. C The balloon’s pressure rises until it explodes. D Nothing happens to the balloon. E The balloon becomes heavier and sinks in water.

Answer: B

Question: Consider two 5 L chambers. One contains 5.00 g O₂, the other 5.00 g He. Which chamber has the higher pressure at room temperature?

Answer Options: A 5.00 g O₂ has the higher pressure. B 5.00 g He has the higher pressure. C Both chambers have the same pressure. D Need additional information to know. E Pressures are indeterminate for these masses.

Answer: B

Question: Which one of the following changes would cause the pressure of a gas to double, assuming volume and moles are held constant?

Answer Options: A Double the absolute temperature. B Halve the absolute temperature. C Double the volume. D Halve the number of moles. E Cool the gas to 0 °C.

Answer: A

Question: If 5.00 g of Gas A and 5.00 g of Gas B are mixed in the same container and the partial pressure of B is twice that of A, what can be inferred about the two gases?

Answer Options: A Gas B has half the molar mass of Gas A. B Gas B has twice the molar mass of Gas A. C Both gases have the same molar mass. D Gas A is diatomic while Gas B is monatomic. E No relationship can be determined.

Answer: A

Question: Which of the following gas samples has the greatest average molecular speed at 25 °C?

Answer Options: A H₂  B He  C N₂  D O₂  E Xe

Answer: A

Question: Even at moderate temperatures, attractions between molecules appear to have little effect on the elasticity of gas–gas collisions because…

Answer Options: A Gas molecules move too slowly for attractions to matter. B Molecules are far apart and collide too briefly for intermolecular forces to act. C Intermolecular attractions are repulsive, not attractive. D Collisions are perfectly inelastic. E Gas pressure neutralizes attractive forces.

Answer: B

Question: For a constant temperature, which of the following gases will have the greatest average speed?

Answer Options: A He  B Ar  C CO₂  D N₂  E Cl₂

Answer: A

Question: How does the root-mean-square velocity of an ideal gas vary as the molar mass of the gas increases?

Answer Options: A It increases linearly with molar mass. B It decreases linearly with molar mass. C It is inversely proportional to the square root of molar mass. D It is independent of molar mass. E It increases exponentially with molar mass.

Answer: C

Question: Which one of the following gases would be expected to have the highest molecular speed if all samples were at the same temperature?

Answer Options: A H₂  B He  C N₂  D O₂  E Cl₂

Answer: A

Question: Under which conditions would xenon (Xe) behave most like an ideal gas?

Answer Options: A Low temperature and high pressure. B Low temperature and low pressure. C High temperature and high pressure. D High temperature and low pressure. E Room temperature and moderate pressure.

Answer: D