1. How many grams of CaCl2 (molar mass 111. g/mol) is needed to prepare 250. mL of a 0.355 M solution of CaCl2 ? A. 0.0888 g B. 9.85 g C. 1.42 g D. 158. g
2. What volume of a 2.00 M solution of hydrochloric acid is needed to prepare 500. mL of a 0.333 M HCl solution ? A. 3.33 x 103 mL B. 12.0 mL C. 83.3 mL D. 8.33 x 10-2 mL
3. What is the molarity (molar concentration) of an HCl solution if 41.5 mL of the HCl solution neutralizes 50.0 mL of 0.250 M Ba(OH)2 ? A. 0.519 M B. 0.151 M C. 0.301 M D. 0.602 M
4. Which of the following aqueous solutions below will result in the formation of a precipitate when mixed ? 1. lithium phosphate and magnesium chloride 2. barium chloride and sodium sulfate 3. ammonium nitrate and calcium chloride 4. potassium carbonate and sodium acetate A. 1 and 2 B. 2 and 3 C. 3 and 4 D. 1 and 4
5. What is the molarity of chloride ion (Cl-) in a solution prepared by mixing 250. mL of a 0.350 M NaCl solution with 150. mL of a 0.250 M CaCl2 solution ? Assume the volumes are additive. A. 0.150 M B. 0.583 M C. 0.313 M D. 0.406 M
6. Which of the following statements are true ? 1. In an endothermic process, heat is absorbed by the system from its surroundings. 2. If a reaction, A ---> B, is exothermic, the reverse reaction, B ---> A, is also exothermic. 3. If the heat released when one mole of water freezes is 6.01 kJ, the heat released when two moles of water freezes is 12.02 kJ. 4. The sign of the enthalpy change for an exothermic reaction depends on the reaction. A. 1 and 2 B. 1 and 3 C. 3 and 4 D. 2 and 4
7. How many grams of CO must react in excess oxygen to release 510. kJ of heat given the thermochemical equation below ? 2 CO(g) + O2(g) = 2 CO2(g) H = -566. kJ A. 50.5 g B. 1.11 g C. 15.3 g D. 25.3 g
8. What temperature change occurs when 3.98 kJ of heat are added to 158 g of gold ? The specific heat of gold is 0.129 J/g C. A. 195 deg C B. 0.195 deg C C. 5.12 deg C D. 5.12 x 103 deg C
9. Given the following data: C3H8(g) + 5 O2(g) = 3 CO2(g) + 4 H2O(l) H = -2220.1 kJ C(graphite) + O2(g) = CO2(g) H = -393.5 kJ H2(g) + 1/2 O2(g) = H2O(l) H = -285.8 kJ What is the enthalpy change ( H) for the following reaction ? 3 C(graphite) + 4 H2(g) = C3H8(g) A. -2.900 x 103 kJ B. -103.6 kJ C. 770.4 kJ D. Cannot be determined from the information given.
10. Which of the indicated variables show a correct relationship ?
A. 1 and 3
B. 2 and 3
C. 2 and 4
D. 3 and 411. A sample of gas initially at 35.0oC and 1.50 atm occupies a volume of 2.50 L. If the pressure remains constant, at what temperature would the volume be 1.25 L ? A. 17.5oC B. 15.4oC C. -119oC D. 343oC
12. What is the molar mass of a gas if 0.797 g of the gas occupies a volume of 458 mL at 735 torr and 25oC ? A. 3.69 g/mol B. 17.0 g/mol C. 5.79 x 10-2 g/mol D. 44.0 g/mol
13. What volume of NH3(g) is formed when 4.50 L of N2(g) is reacted with 12.5 L of H2(g) ? N2(g) + 3 H2(g) = 2 NH3(g) Assume that all gases are at the same temperature and pressure. A. 9.00 L B. 18.8 L C. 8.33 L D. 17.0 L
14. What are the partial pressures of He(g) and H2(g) in a mixture that contains 100 g of He and 100 g of H2 ? The total pressure of the mixture is 600 torr. A. 300. torr He; 300. torr H2 C. 400. torr He; 200. torr H2 B. 200. torr He; 400. torr H2 D. 100. torr He; 500. torr H2
15. Real gases approach ideal behavior under which of the following conditions ? A. low pressures and low temperatures B. low pressures and high temperatures C. high pressures and low temperatures D. high pressures and high temperatures
16. Which of the following statements are true ? 1. The molecular speed of O2(g) is greater than the molecular speed of H2(g) at the same temperature. 2. The average kinetic energy of N2(g) is greater than that of O2(g) at the same temperature. 3. For an ideal gas we assume there are no attractive forces between gas molecules. 4. The average kinetic energy of one mole of O2(g) at 400oC is greater than the average kinetic energy of one mole of O2(g) at 300oC. A. 2, 3, and 4 B. 1 and 2 C. 1 and 3 D. 3 and 4
17. What is the correct order for the rate of diffusion of the following gases from slowest to fastest ? Assume all gases are at the same temperature and pressure. NH3, C2H6, Xe, H2S, F2 slowest ---------------- fastest A. NH3 < C2H6 < Xe < H2S < F2 B. Xe < F2 < H2S < C2H6 < NH3 C. Xe < H2S < C2H6 < F2 < NH3 D. C2H6 < NH3 < H2S < F2 < Xe
18. Under the same conditions of temperature and pressure a gas is found to diffuse at 0.707 times the rate of diffusion of CH4. The molar mass of the gas is A. 3.12 x 10-2 g/mol. B. 11.3 g/mol. C. 32.0 g/mol. D. 22.6 g/mol.
19. Calculate the wavelength (in nm) and the energy of 1 mole of photons that have a frequency of 4.50 x 1015 Hz. Wavelength Energy A. 66.7 nm 1.80 x 106 J/mol B. 1.50 x 107 nm 2.98 x 10-18 J/mol C. 6.67 x 10-8 nm 1.80 x 106 J/mol D. 1.35 x 1015 nm 6.79 x 1049 J/mol
20. Which of the following statements are true ? 1. Planck's successful explanation of the black body radiation spectrum introduced the hypothesis that matter can emit or absorb energy in discrete quantities. 2. The solution to the Schrodinger wave equation for the hydrogen atom does not provide a detailed description of the electron's position but only the probability of finding the electron in a given region of space. 3. The de Broglie relation, lambda = h/mu, equates photon energy to the difference in energy levels of the atom. 4. Einstein's work on the photoelectric effect confirmed that no two electrons can have the same four quantum numbers. A. 1 and 2 B. 2 and 3 C. 3 and 4 D. 1 and 4
21. Which of the following statements are true ? 1. There are four subshells in the energy level whose principal quantum number is 4. 2. There are four orbitals in the 4p sublevel. 3. The allowed values of ml for a 5f sublevel are -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5. 4. A 3d orbital can hold at most 2 electrons. A. 1 and 2 B. 2 and 3 C. 3 and 4 D. 1 and 4
22. The set of quantum numbers n = 6, l = 3, ml = 0 A. describes an electron in a 6f orbital. B. describes one of five orbitals of a similar type. C. describes a 3s orbital. D. is not allowed.
23. Which of the following sets of quantum numbers listed below are correct sets ? n l ml ms A. 3 2 1 0 B. 2 3 -1 1/2 C. 2 2 2 1/2 D. 2 1 0 1/2
24. The atom whose ground state configuration is 1s2 2s2 2p3 is A. C B. N C. O D. F
25. Which of the following have 2 unpaired electrons in their ground states ? 1. Be 2. He 3. C 4. O A. 1 and 2 B. 2 and 3 C. 3 and 4 D. 1 and 4