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Department of Chemistry University of Missouri-St. Louis Name_________________ Practice Exam 2 Chemistry 11 March 2007 1. 10 drops of 0.2 M NaOH solution is placed into a small beaker. If 0.1 M HCl with a small amount of phenolphthalein is added dropwise: a. the solution will become red on the first drop added, then change to colorless after about 5 drops have been added. b. the solution will become red after about 20 drops have been added c. the solution will become red on the first drop added, then change to colorless after about 20 drops have been added. d. the solution will remain colorless, even after large amounts of HCl have been added. e. the solution will be red initially, and become colorless after about 20 drops of HCl have been added. 2. 10 drops of 0.2 M HCl solution with a small amount of phenolphthalein is placed into a small beaker. If 0.1 M NaOH is added dropwise: a. the solution will become red on the first drop added, then change to colorless after about 5 drops have been added. b. the solution will become red after about 20 drops have been added. c. the solution will become red on the first drop added, then change to colorless after about 20 drops have been added. d. the solution will remain colorless, even after large amounts of NaOH have been added. e. the solution will become colorless on the first drop added, and stay that way until about 10 drops of NaOH have been added. 3. From the observation that bubbling Cl2(g) into a solution of KI produces I2, and Cl-, we conclude that a. neither oxidation or reduction is occurring b. Cl2 is oxidized c. I2 is reduced d. I2 is a better oxidizing agent than Cl2 e. Cl2 is a better oxidizing agent than I2 4. Which of the following net ionic equations is completely correct? a. K+(aq) + BaCl2(aq) = Ba2+(aq) + KCl(s) b. Ag+(aq) + Cl-(aq) = AgCl(s) c. HCl(aq) + KOH(aq) = H2O(l) + Cl-aq) + K+(aq) d. Cu(s) + SO3-2(aq) + 2 H+(aq) = Cu2+ + SO2(g) + H2O(l) e. Zn + 2 Cl- = ZnCl2 (s) 1 5. The maximum number of electrons that can occupy the 3p orbitals is a. 5 b. 6 c. 10 d. 14 e. 18 6. Let’s say that you are examining the outermost electrons in a ground-state radium atom. Which of the following sets of values for the four quantum numbers (n, l, ml, and ms) could you use to describe the electrons? a. 6, 1, 1, ½ b. 7, 0, 1, ½ c. 7, 0, 0, -½ d. 7, 1, 0, ½+ e. 7, 2, 1, -½ 7. You are given a solution that contains a Co2+ salt. Based on the activity series shown in Table 4.3 below, which of the following metals would not cause the precipitation of cobalt metal when a strip of that metal is placed in the cobalt solution? a. b. c. d. e. copper chromium calcium magnesium manganese 2 8. A solution of an unknown reducing agent was titrated with 50 mL of a 0.1 M CrO4-2 solution, which causes the chromate to be reduced to Cr3+. If instead of chromate a 0.1 M MnO4-solution had been used that resulted in formation of Mn2+, what volume of permanganate solution would be required? a. 15 mL b. 20 mL c. 30 mL d. 50 mL 9. Which of the following elements has the greatest affinity for electrons? a. K b. Cl c. Zn d. Mg e. S 10. Which of the following equations are balanced? Zn(s) + 2ClO-(aq) + 4 H+(aq) = Zn2+ + Cl2(g) + 2H2O(l) Cu+2 + 2 Zn (s) = Cu (s) + 2 Zn+2 4 C2H6O + 4 MnO4- + 12 H+ = 4 Mn+2 + 4C2H4O2 + 11 H2O none of the above a. b. c. d. 11. What gets oxidized in the reaction: 2 MnO4-(aq) + 10 I-(aq) + 16 H+(aq) ---> 2 Mn2+(aq) + 5 I2(aq) + 8 H2O(l) ? a. b. c. d. e. MnO4IH+ Mn2+ I2 12. The net ionic equation for the neutralization reaction between H2SO4(aq) and NaOH(aq) is: a. H+(aq) + OH-(aq) H2O(l) b. H+(aq) + SO4-2(aq) + Na+(aq) + OH-(aq) Na+(aq) + SO4-(aq) + H2O(l) c. H+(aq) + HSO4-(aq) + Na+(aq) + OH-(aq) NaHSO4(aq) + H2O(l) d. H2SO4 (aq) + 2 NaOH (aq) Na2SO4(aq) + 2H2O(l) e. none of the above 13. a b c d e. What is the oxidation number of Manganese in KMnO4? +2 -2 +6 +7 none of the above 3 13. What is the frequency of a helium-neon laser light with a wavelength of 632.8 nm (632.8x10-9m)? The speed of light is 3.00 x 108 m/s. a. 4.74 x 1014 s-1 b. 4.74 x 105 s-1 c. 2.11 x 10-15 s-1 d. 1.58 x 10-15 s-1 e. none of the above 14. Give n and l quantum numbers for the fourth-shell orbital shown below. a. b. c. d. n = 5 and l = 3 n = 4 and l = 2 n = 4 and l = 1 n = 4 and l = 0 15. Which atom has the largest atomic radius? a. Na b. Cl c. Br d. K 16. What are the possible values of ml if n = 4? a. 5 b. 0, 1, 2, 3, or 4 c. -3, -2, -1, 0, +1, +2, or +3 d. -4, -3, -2, -1, 0, +1, +2, +3, or +4 17. Which of the following atoms has the largest ionization potential ? a. K b. Cl c. Ar d. Ne e. F 4 18. Balance the following equation: Br2 (aq) 2 H2 O + + SO2 (g) Br2 (aq) + SO2 (g) = Br - (aq) + HSO4 - (aq) = 2 Br - (aq) + HSO4 - (aq) + 3H + 19. What is the maximum of pure iodine you could obtain from 100 grams of the mineral lautarite (CaIO3) ? a. b. c. d. 100 g 59.1 g 46.5 g not enough information given 20. The following ions all have the same number of electrons. The order in terms of increasing size is: a. b. c. d. Ti +4, Sc +3, Ca +2, S-2 S-2, Ti +4, Sc +3, Ca +2 S-2, Ca +2 Sc +3, Ti +4 Ca +2, S-2 , Ti +4, Sc +3 Units and Constants h = 6.626 x 10-34 J s J = 1 kg meter2 s-2 c = 3 x 108 m s-1 5