Chapter 12 Learning Objective Practices 1 Define and differentiate initial average and instantaneous rate of reaction 1 In the reaction C4H9Cl aq H2O l C4H9OH aq HCl aq the concentration of the reactant changes from 0 0562 M to 0 0431 M in 85 sec What is the average rate of the reaction over this interval 2 Relate rate of reaction to the rate of change for any reactant or product 2 Given the following balanced equation determine the rate of reaction with respect to NOCl 2 NO g Cl2 g 2 NOCl g A 0 0154 M B 1 54 10 4 moles C 1 54 10 4 M s D 0 0154 M s E 1 54 10 4 moles s A B C t NOCl Rate 1 2 Rate 2 NOCl t NO Rate 1 2 Rate 1 2 NOCl t t D E It is not possible to determine without more information 3 Given the balanced equation if the rate of change of O2 is 0 778 M s what is the rate of change of O3 2 O3 g 3 O2 g A 0 519 M s B 1 56 M s C 2 34 M s D 1 17 M s E 7 78 M s 4 At elevated temperatures dinitrogen pentoxide decomposes to nitrogen dioxide and oxygen 2N2O5 g 4NO2 g O2 g When the rate of change of O2 is 2 2 10 4 M s the rate of change of N2O5 is M s A 2 2 10 4 B 1 1 10 4 C 2 8 10 4 D 5 5 10 4 E 4 4 10 4 5 Hydrogen gas can be made from methane gas by the reaction below How is the rate of change of CH4 related to the rate of change of H2 C H 4 t CH4 g H2O l CO g 3H2 g Page 1 of 7 A H 2 3 t B H 2 3 t C D E H 2 t H 2 t 3 Relate physical state temperature concentration and catalysis to reaction rates 4 Determine a rate law from experimental evidence 6 Determine the rate law and the value of k for the following reaction using the data provided 2 NO g O2 g 2 NO2 g Experiment 1 2 3 NO 0 030 0 030 0 060 O2 M 0 0055 0 0110 0 0055 Initial Rate M 1 s 1 8 55 x 10 3 1 71 x 10 2 3 42 x 10 2 A Rate 57 M 1 s 1 NO O2 B Rate 1 7 103 M 2 s 1 NO 2 O2 C Rate 3 8 M 1 2 s 1 NO O2 1 2 D Rate 3 1 105 M 3 s 1 NO 2 O2 2 E Rate 9 4 103 M 2 s 1 NO O2 2 7 Given the reaction of A2 B2 products The following pictures a and b show two containers with different initial concentrations of A2 and B2 The relative initial rate for a and b is 1 1 What is the order of reaction with respect to A2 A2 B2 A 0 B 1 C 2 D 3 5 Use the rate law to solve for any missing variable 8 Define rate law A An experimentally determined equation that describes how the rate of reaction depends on the concentration of reactants B An experimentally determined equation that describes how the rate of reaction depends on temperature orientation and number of collisions C A theoretical equation that describes how the rate of reaction depends on temperature orientation and number of collisions D A theoretical equation that describes how the rate of reaction depends on the concentration of reactants Page 2 of 7 E A statement that describes how the ratio of reaction depends on concentration of reactants developed from the balanced equation 9 Given the following rate law how does the rate of reaction change if the concentration of Y is doubled 10 Given the following rate law how does the rate of reaction change if the concentration of X is doubled Rate k X Y 2 A The rate of reaction will increase by a factor of 2 B The rate of reaction will increase by a factor of 4 C The rate of reaction will increase by a factor of 5 D The rate of reaction will decrease by a factor of 2 E The rate of reaction will remain unchanged Rate k X Y 2 A The rate of reaction will increase by a factor of 2 B The rate of reaction will increase by a factor of 3 C The rate of reaction will increase by a factor of 5 D The rate of reaction will decrease by a factor of 2 E The rate of reaction will remain unchanged Time s 0 10 20 30 A3 M 4 00 10 4 2 00 10 4 1 00 10 4 5 00 10 5 A2 M 3 00 10 4 4 50 10 4 0 11 A concentration time study of the gas phase reaction 2 A3 3 A2 produced the data in the table below What is the concentration of A2 after 30 seconds A 5 00 10 4 M B 5 50 10 4 M C 5 25 10 4 M D 6 00 10 4 M 12 The hydrolysis of tert butyl chloride is given in the reaction below If the rate law is Rate k CH3 3CCl what is the order of the reaction with respect to water CH3 3CCl aq H2O l CH3 3COH aq H aq Cl aq A zero B first C second D third 6 Use the integrated rate laws to be able to solve for initial concentration time rate constant and final concentration given information on the remaining variables 13 The first order decomposition of N2O at 1000 K has a rate constant of 0 76 s 1 If the initial concentration of N2O is 10 9 M what is the concentration of N2O after 9 6 s A 1 0 10 3 M D 3 6 10 3 M B 8 7 10 3 M E 7 4 10 3 M C 1 4 10 3 M 14 The first order reaction SO2Cl2 SO2 Cl2 has a rate constant equal to 2 20 10 5 s 1 at 593 K What Page 3 of 7 percentage of the initial amount of SO2Cl2 will remain after 2 00 hours A 85 4 B 1 00 C 17 1 D 14 7 15 The first order reaction 2 N2O g 2 N2 g O2 g has a rate constant equal to 0 76 s 1 at 1000 K How long will it take for the concentration of N2O to decrease to 42 of its initial concentration A 1 8 s B 1 1 s C 2 4 s D 0 88 s 7 Determine reaction order from graphs of concentration versus time or from the units of the rate constant 16 What are the units of k in the following rate law Rate k X …