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Unformatted text preview: Version 286 Final Exam Holcombe (52460) 1 This printout should have 50 questions. Multiplechoice questions may continue on the next column or page find all choices before answering. 001 10.0 points What is the rate law for the reaction A + B C ? The following data were collected. Exp [A] [B] Initial Rate 1 0.5 1.2 1 . 40 10 3 2 1.7 1.2 1 . 40 10 3 3 0.5 0.7 4 . 76 10 4 1. rate = 5 . 6 10 3 [A] 2 [B] 2. rate = 9 . 72 10 4 [A] [B] 2 correct 3. rate = 1 . 94 10 3 [A] [B] 2 4. rate = 2 . 33 10 3 [A] [B] 2 5. rate = 4 . 67 10 3 [A] 2 [B] 1 Explanation: 002 10.0 points The solubility product constant of AgCl is 1 . 8 10 10 and that of AgBr is 3 . 3 10 13 . Solid AgNO 3 is slowly added to a solution containing 0.0010 M each of NaCl and NaBr. What concentration of Br would remain in solution when AgCl begins to precipitate? 1. 5 . 5 10 1 M 2. 1 . 8 10 6 M correct 3. 5 . 5 10 4 M 4. 1 . 8 10 4 M 5. 1 . 8 10 10 M Explanation: 003 10.0 points When we put sugar in water it melts. 1. False correct 2. True Explanation: Sugar dissolves in water and melts when its temperature is raised above its melting point. 004 10.0 points The equilibrium constant (dimensionless) for A B is 2. If the initial concentrations of A and B are each 1.0 M, what are the final concentra tions of A and B respectively? 1. [A] = 0.67 M; [B] = 0.33 M 2. [A] = 1.00 M; [B] = 2.00 M 3. [A] = 0.67 M; [B] = 1.33 M correct 4. [A] = 0.50 M; [B] = 1.00 M 5. [A] = 1.00 M; [B] = 1.33 M Explanation: K = 2 [A] ini = 1 . 0 M [B] ini = 1 . 0 M Q = [B] [A] = 1 . 1 . = 1 . &lt; K = 2 Therefore, the equilibrium moves to the right. A B(g) ini, M 1 . 1 . , M x x eq, M 1 . x 1 . 0 + x K = [B] [A] = 2 1 . 0 + x 1 . x = 2 1 . 0 + x = 2 . 2 x x = 0 . 33 [A] = 1 . x = 0 . 67 M [B] = 1 . 0 + x = 1 . 33 M Version 286 Final Exam Holcombe (52460) 2 005 10.0 points In a sample of pure water at 25 C, the ratio [H 3 O + ] [OH ] is equal to 1. 14.0 2. 7.0 3. 1.0 correct 4. 1 . 10 14 5. 1 . 10 7 Explanation: 2 H 2 O H 3 O + + OH let x = [H 3 O + ] = [OH ] , K w = [H 3 O + ][OH ] = x 2 = 10 14 x = 10 7 so [H 3 O + ] [OH ] = 10 7 10 7 = 1 006 10.0 points Consider the following pressure diagram for a binary liquid containing A and B. 1 x A 50 torr 90 torr A solution is mixed such that x A = 0 . 45. What is the vapor pressure of B? 1. 68 torr 2. 27 torr correct 3. 40 torr 4. 90 torr 5. 50 torr Explanation: 1 . 45 90 torr 27 torr b 007 10.0 points Zinc Copper 1 . 10 V V Voltmeter e e 1 M Zn 2+ (aq) 1 M Cu 2+ (aq) Salt bridge to carry ions In this electrochemical cell, what is the an ode?...
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 Spring '08
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