February 16, 2012Gas constant, R = 8.314 J/K  molCHEM 188 – Spring, 2012Hour Exam 1 (Red)February 16, 2012Instructions:Your scantron answer sheet must show your NAME, 7-DIGIT KU ID NUMBER, and LAB SECTION. (Begin these entries at the LEFT end of the space provided.)In answering the questions, be careful to fill in the corresponding circles on the answer sheet according to the number of the question on the exam. USE A SOFT (No. 2) PENCIL.Useful information:Gas constant, R = 8.314 J/K  mol = 0.08206 L  atm/K  mol Integrated Rate Laws: kt[A]1[A]1 :orderSeconde[A] [A] :order-Firstkt - [A] [A] :order-Zero0kt00Arrhenius equation: /RT-Ea Ae k  2121a21TTTTRE kklnRelation of KP to KC: KP = KC(RT)n Quadratic formula: aacbbx24211. Consider the reaction N2(g) + 3H2(g) 2NH3(g)Suppose that the rate of loss of molecular nitrogen, d[N2]/dt, is 0.060 M/s at a particular time during the reaction. What is the rate of formation of ammonia, d[NH3]/dt? A. 0.020 M/s B. 0.030 M/s C. 0.060 M/s D. 0.12 M/s E. 0.18 M/s2. For the overall chemical equation, 2H2S(g) + O2(g)  2S(s) + 2H2O(l)which one of the following can you rightly assume?A. The reaction is third-order overall.B. The reaction is second-order overall.C. The rate law is, rate = k[H2S][O2]D. The rate law is, rate = k[H2S]2[O2]E. The rate law cannot be determined from the information given.3. The reaction A + 2B  products was found to have the rate law, rate = k[A] [B]2. Predict by what factor the rate of reaction will increase when the concentration of A is doubled and the concentration of B is also doubled.A. 2 B. 4 C. 6 D. 8 E. 94. Consider the hypothetical reaction A + 2B  products. Use the following data to determine the rate of the reaction when [A] = 0.10 M and [B] = 0.15 M. Expt. # [A]0 [B]0 Initial rate 1 0.20 0.20 0.76 M/s 2 0.20 0.40 0.76 M/s 3 0.40 0.20 1.52 M/s A. 0.19 M/s B. 0.38 M/s C. 0.57 M/s D. 0.95 M/s E. none of these5. If concentration is expressed in units of moles per liter (mol/L) and time in units of seconds (s),the units of a third-order rate constant areA. L mol 1 s 1B. L2 mol 2 s 1 C. s  1D. s  2E. mol L 1 s 16. A certain first-order reaction A  B is 75% complete in 8.0 minutes at 25oC. What is the half-life of the reaction?A. 4.0 min B. 8.0 min C. 16 min D. 19 min E. 39 min27. For a certain reaction, A  products, it was found that 20 minutes were required for the concentration of A to decrease from 1.0 M to 0.50 M, and that an additional 20 minutes were required for [A] to decrease from 0.50 M to 0.25 M. What is the rate law for this reaction?A. rate = k[A]1B. rate = kC. rate = k[A]D. rate = [A]2E. cannot be determined from the information given8. The rate constant for the second-order reaction 2NO2(g)  2NO(g) + O2(g)is 0.54 M 1s 1 at 300oC. If the initial concentration of NO2 was 0.50 M, what would the concentration of NO2 be after 10 sec?A. 0.10 M B. 0.14 M C. 0.21 M D. 0.28 M E. 0.39 M9. A certain zero-order reaction A  B for which [A]o = 1.0 M is 45% complete in 13 seconds 25oC. What the rate constant, k, for this reaction at 25oC?A. 0.012 M/s B. 0.023 M/s C. 0.035 M/s D. 0.046 M/s E. 0.058 M/s10. The isomerization of cyclopropane follows first-order kinetics. The rate constant at 600 K is 2.72 x 107 min1, and the activation energy for the reaction is 270 kJ/mol. Calculate the value of the rate constant (in min1) at 900 K.A. 6.20 x104 B. 2.05 x 101 C. 1.86 x 101D. 6.87 x 102 E. 1.32 x 10411. For a certain second-order reaction, rate constant (k) at 25oC is 0.235 M1 s1. At 50oC the rate constant is 0.959 M1s1. What is the frequency factor, A, for this reaction in units of M1s1?A. 4.26  104B. 3.21  105C. 2.41  106D. 1.82  107E. 1.37  10812. If a catalyst could be found that would lower the activation energy by 15.0 kJ/ mol for a particular reaction, by what factor would the rate constant for this reaction be increased at 25oC? (Assume the frequency factor remains the same.)A. 5.66 x 101 B. 4.26 x 102 C. 3.20 x 103 D. 2.41 x 104 E. 1.81 x 105 313. Dinitrogen monoxide (N2O) decomposes according to the balanced equation 2N2O(g)  2N2(g) + O2(g)A proposed reaction mechanism involving three steps is shown below. Pick out all of the reaction intermediates in the following mechanism: Br2(g)  2Br(g) Br(g) + 2N2O(g)  N2(g) + BrO(g) (occurs twice) 2BrO(g)  Br2(g) + O2(g)A. Br B. Br2C. BrO D. N2O E. Br and BrO14. For the following reaction (NH4)2Se(s)  2NH3(g) + Se(s)the correct expression for the equilibrium constant KC is …A. [NH3][ Se]/[ (NH4)2Se]B. [NH3]2[ Se]/[ (NH4)2Se]C. [(NH4)2Se]/[NH3]2[ Se]D. [NH3]2E. [NH3]15. The equilibrium constant, KC, for the reaction 2NO(g) + O2(g)  2NO2(g).is found to be 6.44 x 10 5 at 25oC. What is the value of KC at 25oC for the reaction NO(g) + 1/2O2(g)  NO2(g).A. 802 B. 3.22 x 10 5 C. 6.44 x 10 5D. 1.28 x 10 6 E. 4.15 x 10 1116. At 375oC, the equilibrium constant, KC, is 1.22 for the reaction N2(g) + 3H2(g)  2NH3(g) Calculate KP for this equilibrium at this temperature. A. 4.31 x 10 4 B. 2.29 x 10 3 C. 1.22 D. 6.49 x 10 E. 3.45 x 103 417. For the reaction H2(g) + I2(g)  2HI(g) Kc = 50.2 at 445oC.If [H2] = [I2] = 0.100 M and [HI] = 0.750 M at 445oC, which one of the following statements is(are) true? 1. The system is at equilibrium; no change will occur. 2. The concentration of H2 will increase as the system approaches equilibrium. 3. The concentration of HI will increase as the system approaches equilibrium. 4. The concentration of I2 will decrease as the system approaches equilibrium. 5. The concentration of HI will decrease as the system approaches equilibriumA. 1 only B. 2 only C. 3 only D. 2 & 5 E. 3 & 418. The equilibrium constant, KP, for the decomposition of phosphorus pentachloride PCl5(g)  PCl3(g) + Cl2(g)is found to be 1.05 at 250oC. If the equilibrium concentrations of PCl5 and PCl3 are 0.875