Question 1 The rate of popcorn popping at different temperatures was found to be described by the Arrhenius equation. How many times faster does the popcorn pop at 210°C compared with that at 180°C when the activation energy is 167 kJ/mol? Question 2 Given the following data determine the rate law for the reaction 2NO(g) Cl2(g)® 2NOCl(g) Experiment [NO] (M) [Cl2] (M) Rate(M/s) 1 0.0300 0.0100 3.4´ 10–4 2 0.0150 0.0100 8.5´ 10–5 3 0.0150 0.0400 3.4´ 10–4 Question 3 The disappearance of HI in the reaction 2HI(g)® I2(g) H2(g) is shown in the following figure. What is the instantaneous rate of this reaction at t = 5 s if the instantaneous rate of change of [HI] is 0.02 M/s? Question 4 A proposed mechanism for the reduction of nitrogen as NO by hydrogen is: Step 1: H2(g) 2NO(g)® N2O(g) H2O(g) Step 2: N2O(g) H2(g)® N2(g) H2O(g) What is the molecularity of step 1? Question 5 Given the following data determine the order of the reaction with respect to NO(g). 2NO(g) Cl2(g)® 2NOCl(g) Experiment [NO] (M) [Cl2] (M) Rate (M/s) 1 0.0300 0.0100 3.4´ 10–4 2 0.0150 0.0100 8.5´ 10–5 3 0.0150 0.0400 3.4´ 10–4 Question 6 The following figure shows Arrhenius plots for four different reactions. Which reaction has the least temperature dependence? Question 7 The reaction 2NO(g) O2(g) ® 2NO2(g) has the following rate law: Rate = k[O2][NO]2. If the concentration of NO is reduced by a factor of two the rate will ________ Question 8 For the rate law Rate = k[A][B]1/2 the partial order with respect to A is ________ thepartial order with respect to B is ________ and the total order is ________. Q question 9 For the rate law Rate = k[A]3/2[B] the partial order with respect to A is ________ the partial order with respect to B is ________ and the total order is ________. Question 10 A proposed mechanism for the decomposition of ozone in the stratosphere is: Step 1: Cl(g) O3(g)®ClO(g) O2(g) Step 2: ClO(g) O3(g)® Cl(g) 2 O2(g) What is the molecularity of step 2? Question 11 For the reaction 2A 3B® 4C 5D the rate of the reaction in terms ofDB would be written as ________ Which of the following statements must be true of an intermediate in a reaction mechanism? Is produced in an elementary step. II. Is consumed in an elementary step. III. Is included in the overall balanced reaction equation. Question 12 The energy needed to form an activated complex is called Question 13 Nitric oxide and nitrogen dioxide are found in photochemical smog. Nitrogen dioxide is formed from nitrogen monoxide in the exhaust of automobile engines. A possible mechanism for this reaction is given below where equilibrium is quickly established in steps 1 and 2. What is the rate law predicted by this mechanism? Reaction: 2NO(g) O2(g)® 2NO2(g) Step 1 (fast): NO NOD N2O2 Step 2 (fast): N2O2D N NO2 Step 3 (slow): N O2® NO2
