Sample Questions Chem 22 Student Chapters 13-18 Page 1 of 5 1. The vapor pressure of a liquid is the pressure, at equilibrium, of the a) solid above its liquid. b) liquid above its solid. c) gas above its liquid. d) liquid above its gas. Section Reference 1: Section 13.2 2. Which segment in the following figure indicated by letters corresponds to melting? a) AB b) BC c) CD d) DE Section Reference 1: Section 13.4 3. The boiling point temperature of a liquid is the temperature at which its vapor pressure a) is less than the external pressure. b) is greater than the external pressure. c) is equal to the external pressure. Section Reference 1: Section 13.3 4. Approximately, what percentage of the Earth s surface is covered with water? a) 25 % b) 50 % c) 75 % d) 100 % Section Reference 1: Section 13.7 5. Which substance contains molecules that will not form hydrogen bonds? a) hydrogen b) hydrogen fluoride c) water d) ammonia Section Reference 1: Section 13.5 6. A solution is a A. homogeneous compound. B. heterogeneous compound. C. homogeneous mixture. D. heterogeneous mixture. Reference: Section: 14.5 7. As temperature increases, the solubility of a gas in water A. increases. B. decreases. C. remains the same. 8. The dissolved solute is in equilibrium with undissolved solute in a solution which is A. saturated. B. unsaturated. C. supersaturated. 9. The normal boiling point of pure water is 373 K. As a solute dissolves in water, the boiling point of the solution will A. increase. B. decrease. C. remain the same. 10. Write the balanced chemical equations for the removal of water from the following hydrated crystals. A. Copper(II)sulfate pentahydrate B. Tin(II)chloride dihydrate C. Cobalt(II)chloride hexahydrate D. Magnesium sulfate heptahydrate
Sample Questions Chem 22 Student Chapters 13-18 Page 2 of 5 11. A cup of coffee has a volume of 250. ml, a mass of 250. g, and contains 125 mg of caffeine, C 8 H 10 N 4 O 2. What is the mass percent of the caffeine in the coffee? Section Reference 1: Section: 14.4 12. For the following neutralization reaction: sulfuric acid plus potassium hydroxide yields potassium sulfate plus water A. Write the balanced formula equation. B. Write the net ionic equation. Section Reference 1: Section 15.6 and 15.7 13. Arrhenius defined an acid as a substance whose aqueous solution contains an excess of A. sodium ion. B. hydroxide ion. C. chloride ion. D. hydrogen ion. 14. Acids react with carbonates to produce the gas A. hydrogen. B. carbon dioxide. C. nitrogen. D. oxygen. 15. An amphoteric substance is one that A. may react as an acid or a conjugate acid B. may react as a salt C. may react as a base or a conjugate base D. may react as an acid or a base 16. What is the ph of a 0.034 M hydrochloric acid solution? A. -2 B. 3.4 C. -1.5 D. 1.5 17. Equilibrium is reached in a chemical reaction when A. the reactants are completely consumed. B. the concentrations of all reactants and products become equal. C. the rates of the opposing reactions become equal. D. the forward and reverse reactions stop. Reference: Section 16.3 18. According to Le Châtelier s Principle, decreasing the temperature at which the following reaction takes place will A. shift the equilibrium to the left. B. shift the equilibrium to the right. C. have no effect on the equilibrium. Reference: Section 16.4 N 2 O 4 + 58.6 kj 2NO 2 (g) 19. In which direction will the point of equilibrium shift when the pressure is increased in the following equilibrium? N 2 (g) + 3 H 2 (g) 2 NH 3 (g) Reference: Section 16.5 20. In which direction will the point of equilibrium shift when temperature is increased in the following equilibrium? 2 SO 3 (g) + 188 kj 2 SO 2 (g) + O 2 (g) Reference: Section 16.7
Sample Questions Chem 22 Student Chapters 13-18 Page 3 of 5 21. In which direction will the point of equilibrium shift when a catalyst is added to the following equilibrium system? 2 C (s) + O 2 (g) 2 CO (g) + 110 kj Reference: Section 16.8 22. Calculate the value of K eq for the following equilibrium when [ H 2 ] = 0.228 M, [ I 2 ] = 0.228 M, and [ HI ] =1.544 M. H 2 (g) + I 2 (g) 2 HI (g) A. 29.7 B. 0.0337 C. 0.0219 D. 45.9 Reference: Section 16.9 23. Which acid ionization constant would indicate the strongest acid? A. 3.5 10-4 B. 9.5 10-8 C. 1.5 10-2 D. 1.3 10-13 Reference: Section 16.11 24. A solution in which equilibrium is reached between dissolved and undissolved solute is A. saturated. B. unsaturated. C. supersaturated. Reference: Section 16.12 25. Which species is oxidized in the following equation? 2 H 2 O 2 H 2 + O 2 A. H 2 B. O 2 C. H +1 D. O -2 26. What is the oxidation number of manganese in MnO 2? A. +2 B. -4 C. +4 D. 0 27. Which occurs when a sodium atom is oxidized? A. One electron is gained B. One electron is lost C. One proton is gained D. One proton is lost 28. Which occurs when an oxygen atom is reduced? A. Two protons are gained B. Two protons are lost C. Two electrons are gained D. Two electrons are lost 29. The reducing agent is A. the species that is reduced. B. the species with a negative charge. C. the species that loses electrons. D. the species that gains electrons. Reference: Section 17.2 30. In the following reaction, the chlorine atoms 2 Na + Cl 2 2 NaCl A. gain electrons. B. lose electrons. C. gain protons. D. lose protons. Reference: Section 17.3 31. What always occurs at the cathode in an electrolytic cell? A. Protons are gained B. Protons are lost C. Electrons are gained D. Electrons are lost Reference: Section 17.8
Sample Questions Chem 22 Student Chapters 13-18 Page 4 of 5 32. In a voltaic cell A. a chemical reaction occurs spontaneously and releases energy as electricity. B. electricity causes a chemical reaction to occur. C. a physical change occurs spontaneously and releases energy as electricity. D. electricity causes a physical change to occur. Reference: Section 17.8 33. The instrument used to measure ionizing radiation is a A. radioactive counter. B. Curie counter. C. Roentgen counter. D. Geiger counter. Reference: Section 18.7 34. Gamma radiation has A. a mass of 4 amu. B. a charge of +2. C. a charge of -1. D. neither mass nor charge. 35. An alpha particle has A. a mass of 2 amu. B. a mass of 4 amu. C. a charge of -1. D. neither mass nor charge. 36. A beta particle has A. a mass of 4 amu. B. a charge of +4. C. a charge of -1. D. neither mass nor charge. 37. In which type of reaction does a heavy nucleus absorb a neutron, split to form two or more intermediate sized fragments, and release at least two neutrons? A. Alpha decay B. Beta decay C. Fission D. Fusion Reference: Section 18.8 38. In which type of reaction do the nuclei of two light elements unite to form a heavier nucleus? A. Fission B. Fusion C. Alpha decay D. Beta decay Reference: Section 18.11 39. Which form of nuclear emission requires the greatest amount of shielding to provide protection from radiation injury? A. Alpha B. Beta C. Gamma 40. Which form of nuclear emission requires the least amount of shielding to provide protection from radiation injury? A. Alpha B. Beta C. Gamma 41. How many neutrons are in the nucleus of cobalt-60? A. 29 B. 31 C. 27 D. 33 Reference: Section 18.1 42. What type of emission causes C-14 to decay to N-14? A. Alpha B. Beta C. Positron D. Gamma 43. When Kr-85 emits gamma radiation, the remaining nucleus is A. Rb-85 B. Se-81 C. Kr-85 D. Rb-84 Reference: Section 18.5
Sample Questions Chem 22 Student Chapters 13-18 Page 5 of 5 44. Use the activity series at the right More active K to predict whether each of the Ba following reactions will occur Ca spontaneously. Na Mg Al Zn Cr Fe A. Fe + Ca(NO 3 ) 2 B. Mg + Zn(NO 3 ) 2 C. K + Zn(NO 3 ) 2 D. Cr + NaNO 3 E. Mg + Ca(NO 3 ) 2 F. Ba + Al(NO 3 ) 3 Reference: Section 17.5 45. Define the term half-life. Why are half-lives important when using radioactive tracers for medical purposes?