1. One mole of which gas has the greatest density at STP? A) CO2 B) Ar C) Kr D) All three gases have the same density.

2. Calculate the root mean square velocity for the O2 molecules in a sample of O2 gas at 11.8°C. (R = 8.3145 J/K mol) A) 95.94 m/s B) 14.89 m/s C) 471.1 m/s D) 272.1 m/s

3. Which of the following properties of a real gas is related to the b coefficient in the van der Waals equation? A) Real gases consist of molecules or atoms that have volume. B) The average speed of the molecules of a real gas increases with temperature. C) There are attractive forces between atoms or molecules of a real gas. D) The rate of effusion of a gas is inversely proportional to the square root of the molecular weight of the gas.

4. Aqueous solutions of sodium sulfide and copper(II) chloride are mixed together. Which statement is correct? a . A) Both NaCl and CuS precipitate from solution. B) No reaction will occur. C) CuS will precipitate from solution. D) NaCl will precipitate from solution.

5. Which statement is true of a process in which one mole of a gas is expanded from state A to state B? a . A) When the gas expands from state A to state B, the surroundings are doing work on the system B) The amount of work done in the process must be the same, regardless of the path. C) It is not possible to have more than one path for a change of state. D) The final volume of the gas will depend on the path taken.