NO CALCULATORS MAY BE USED FOR THESE QUESTIONS Questions 1-3 refer to the following gases at 0 C and 1 atm. (A) Ar (B) NO 2 (C) Xe (D) H 2 (E) N 2 1. Has an average atomic or molecular speed closest to that of CO molecules at this temperature and pressure. 2. Has the greatest rate of effusion through a pinhole in a container. 3. Has the greatest density at this temperature and pressure. Questions 4-6 refer to four gases in identical rigid containers under the conditions given in the table below. Container A B C D Gas Methane Ethane Propane Butane Molar Mass (g/mol) 16 30 44 58 Temperature ( C) 27 27 27 27 Pressure (atm) 2.0 4.0 2.0 2.0 4. The average kinetic energy of the gas molecules is (A) Greatest in container A (B) Greatest in container B (C) Greatest in container C (D) Greatest in container D (E) The same in all three containers 5. The density of the gas, in g/l, is (A) Greatest in container A (B) Greatest in container B (C) Greatest in container C (D) Greatest in container D (E) The same in all three containers 6. If the pressure of each gas is increased at a constant temperature until each gas condenses, which gas will condense at the lowest pressure? (A) Methane (B) Ethane (C) Propane (D) Butane (E) All the gases will condense at the same pressure.
7. The figure above represents three sealed 1.0 L rigid containers, each containing a noble gas at 298 K. The pressure of Ne in the first container is 2.0 atm. After all the gases are combined in a previously evacuated 2.0 L rigid container, what is the total pressure of the gases at 298 K? (A) 3.0 atm (B) 4.5 atm (C) 6.0 atm (D) 9.0 atm (E) 12.0 atm 8. The graph above shows the speed distribution of molecules in a sample of a gas. Which of the following graphs shows the speed distribution of the same molecules at a lower temperature? (A) Curve A (B) Curve B (C) Curve C (D) Curve D (E) All curves are at the same temperature.
9. A flask contains 0.50 mole of He (g), 0.50 mole of Ne (g), and 0.50 mole of Ar (g). The total pressure of the gases in the flask is 600 mmhg. What is the partial pressure of the He (g) in the flask? (A) 120 mmhg (B) 200 mmhg (C) 300 mmhg (D) 400 mmhg (E) 480 mmhg 10. Propane gas, C 3 H 8, burns in excess oxygen gas. When the equation for the reaction is correctly balanced with coefficients in terms of lowest whole-number, the coefficient for O 2 (g) is (A) 1 (B) 3 (C) 4 (D) 5 (E) 10 Gas Amount He 1.00 mol Ne 0.25 mol Ar 0.25 mol 11. Three gases in the amounts shown in the table above are added to a previously evacuated rigid tank. If the total pressure in the tank is 6.0 atm at 25 C, the partial pressure of He (g) in the tank is closest to (A) 1.00 atm (B) 2.00 atm (C) 3.00 atm (D) 4.00 atm (E) 6.00 atm 12. At what temperature and pressure would a gas be most likely deviate from ideal behavior? Temperature (K) Pressure (atm) (A) 100 30 (B) 100 3 (C) 100 1 (D) 400 1 (E) 400 3
CH 4 (g) + 2 O 2 (g) CO 2 (g) + 2 H 2 O (g) 13. When 1.0 mol of CH 4 (g) reacts completely as possible with 1.0 mol of O 2 (g) according to the equation above, the total number of moles of reaction products is (A) 0.75 mol (B) 1.0 mol (C) 1.5 mol (D) 3.0 mol (E) 4.5 mol 14. Of the following gases, which has the greatest average molecular speed at 298 K? (A) Cl 2 (B) NO 2 (C) N 2 (D) Kr (E) PH 3 15. Given the Pressure-Volume Diagram above, which point on the graph best represents an ideal gas? (A) Point A (B) Point B (C) Point C (D) Point D (E) Point E 16. A sample of 4.00 grams of an ideal gas at 300 K and 1.50 atmospheres pressure has a volume of 2.00 liters. What is the molar mass of the gas? The gas constant, R, is 0.08 (L atm)/(mol K). (A) 2 gram/mole (B) 28 grams/mole (C) 30 grams/mole (D) 32 grams/mole (E) 44 grams/mole
17. Hydrogen gas, H 2, is collected over water at 25 C and is measured to be 700 millimeters of mercury. At this temperature, the vapor pressure of water is 25 millimeters of mercury. The partial pressure of H 2 (g) in the system is (A) 25 mmhg (B) 50 mmhg (C) 675 mmhg (D) 700 mmhg (E) 725 mmhg 18. A sample of oxygen gas, O 2, effuses at the rate of 0.10 moles per minute. Under the same conditions, which of the following gases effuses approximately 4 times faster? (A) H 2 (B) He (C) N 2 (D) CO 2 (E) Cl 2 19. Equal masses of He and Ne are placed in a sealed container. What is the partial pressure of He if the total pressure in the container is 12 atm? (A) 2 atm (B) 4 atm (C) 6 atm (D) 8 atm (E) 10 atm 20. At standard temperature and pressure, a 2.0 mol sample of He gas and a 1.0 mol sample of Ne gas have the same (A) Density (B) Rate of effusion (C) Average kinetic molecular energy (D) Average molecular speed (E) Volume