Transcript
General Chemistry: Atoms First, 2e (McMurry and Fay) Chapter 12 The Rates and Mechanisms of Chemical Reactions
12.1 Multiple Choice Questions 1) Which term describes the measure of the increase in the concentration of a product per unit u nit time? A) activation energy ) !inetics C) reaction rate ") reaction time Ans#er$ C "iff$ 1 %opic$ %opic$ &ection 12.1 'ates of Chemical 'eactions 'eactions 2) (nstantaneous rate( is defined as the A) change in concentration per unit time. ) e*uation sho#ing ho# the rate depends on the concentration of each reactant. C) rate of reaction at a particular time. ") rate of reaction during a time interval. Ans#er$ C "iff$ 1 %opic$ %opic$ &ection 12.1 'ates of Chemical 'eactions 'eactions +) Molecular hydrogen can be made from methane gas by the reaction belo#. ,o# is the rate of disappearance of C,- related to the rate of appearance of ,2?
/? C,- 0 g g ) ,2 0l 0l ) 3 C 0 g ) +,2 0 g g )
A) ) C) + ") none of these Ans#er$ "iff$ 2 %opic$ %opic$ &ection 12.1 'ates of Chemical 'eactions 'eactions
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-) %he burning of propane can be represented by the follo#ing e*uation$ 0 g g ) 4 0 g g ) 3 + 0 g g ) - 0 g g ) %he general rate of this reaction may be e5pressed as$ A) ) C) ") Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.1 'ates of Chemical 'eactions 'eactions 6) %he burning of propane can be represented by the follo#ing e*uation$ 0 g g ) 4 0 g g ) 3 + 0 g g ) - 0 g g ) Which of the follo#ing relationships is true? A)
/
) 4
/-
C) +
/4
") 4
/-
Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.1 'ates of Chemical 'eactions 'eactions
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7) Methanol can be produced by the follo#ing reaction$ C0 g g ) 2 ,20 g g ) 3 C,+,0 g g ). ). ,o# is the rate of disappearance of hydrogen gas related to the rate of appearance of methanol?
/?
A) ) C) 2 ") none of these Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.1 'ates of Chemical 'eactions 'eactions 4) ,ydro*uinone8 ,C7,7,8 can be formed by the reaction #ith acetylene belo#$ 2 ,CC, + C ,2 3 ,C7,-, C2 ,o# is the rate of disappearance of acetylene8 ,CC,8 related to the appearance of hydro*uinone 0,*)?
/?
A) ) C) ") Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.1 'ates of Chemical 'eactions 'eactions
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9) %he reaction that occurs in a reathaly:er8 a device u sed to determine the alcohol level in a person;s bloodstream8 is given belo#. f the rate of appearance of Cr 20&-)+ is 1.2- mol.-1+ mol.927 mol mol.4>> mol mol mol mol) %he decomposition of dinitrogen pento5ide is described by the chemical e*uation 2 @260 g g ) 3 - @ 20 g g ) 20 g g ) f the rate of appearance of @2 is e*ual to >.67> mol.1-> mol.29> mol mol.7>> mol mol mol mol seconds of the reaction if 1.>> of ,22 reacts at 26BC and 1.>> atm pressure?
A) .> 1>4 M7 M6 M- M -.>> 1> F> 1> 2.>> 1> F- +.>> 1> F2> 1.>> 1> F- -.6> 1> F+> 6.>> 1> F6 ? What is the average rate of decomposition deco mposition of A+ in the time interval 2>+> seconds? A) -.>> 1> F- M 1> F6 M> 1> F7 M> 1> F7 M -.>> 1> F> 1> 2.>> 1> F- +.>> 1> F2> 1.>> 1> F- -.6> 1> F+> 6.>> 1> F6 ? What is the average rate of formation of A2 in the time interval 2>+> seconds? A) 7.>> 1> F- M F6 M 1> F7 M> 1> F7 M -.>> 1> F> 1> 2.>> 1> F- +.>> 1> F2> 1.>> 1> F- -.6> 1> F+> 6.>> 1> F6 ? What is the concentration of A2 after +> seconds? A) 6.>> 1> F- M ) 6.26 1> F- M C) 6.6> 1> F- M ") 7.>> 1> F- M Ans#er$ "iff$ + %opic$ %opic$ &ection 12.1 'ates of Chemical 'eactions 'eactions 17) Which statement is true for the general rate la#$ 'ate / k DAE DAEmDEn? A) t can be #ritten from the stoichiometry of the ov erall reaction. ) %he overall order of the reaction is e*ual to m times n. C) %he values for the e5ponents must be determined by e5periment. ") %he e5ponents in the rate la# must be positive integers. Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder F ED, 14) %he reaction sho#n belo# has the rate la#$ 'ate / k Dr Dr+ F EDr EDr ED,E2. F 0aq) r+ F 0aq) aq) 6 r aq) 7 ,0aq) aq) 3 + r 20aq) aq) + ,20l 0l ) What is the overall order of reaction? A) first ) second C) third ") fourth Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder
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19) Gor a reaction that follo#s the general rate la#8 'ate / k DAEDE DAEDE28 #hat #ill happen to the rate of reaction if the concentration of A is increased by a factor of +.>>? %he rate #ill A) decrease by a factor of 1<.>>. ) decrease by a factor of 1<+.>>. C) increase by a factor of +.>>. ") increase by a factor of .>>. Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder Algo. ption$ algorithmic 1) Gor a reaction that follo#s the general rate la#8 'ate / k DAEDE DAEDE28 #hat #ill happen to the rate of reaction if the concentration of is increased by a factor of 2.>>? 2.> >? %he rate #ill A) decrease by a factor of 1<-.>>. ) decrease by a factor of 1<2.>>. C) increase by a factor of 2.>>. ") increase by a factor of -.>>. Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder Algo. ption$ algorithmic 2>) %he reaction bet#een chlorine and nitric o5ide to form nitrosyl chloride is sho#n belo#. f the reaction rate doubles #hen the concentration of Cl2 is doubled and the rate *uadruples #hen the concentration of @ is doubled8 by #hat factor #ill the rate increase if both concentrations8 @ and Cl28 are doubled? Cl20 g g ) 2 @0 g ) 3 2 @Cl0 g ) A) 2 ) C) 9 ") 17 Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder 21) %he hydrolysis of tertbutyl chloride is given in the reaction belo#$ 0C,+)+CCl0aq CCl0aq)) ,20l 0l ) 3 0C,+)+C,0aq C,0aq)) ,0aq) aq) Cl0aq) aq) f the rate la# is$ 'ate / k D0C, D0C,+)+CClE8 #hat is the order of the reaction #ith respect to #ater? A) :ero ) first C) second ") third Ans#er$ A "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder Copyright © 2014 Pearson Education, Inc.
22) Hiven the follo#ing hypothetical reaction$ 2 I0 g g ) G0 g ) H0 g g ) 3 products. f the rate la# is$ 'ate / k DIE DIE2DGE18 #hat is the order of reaction #ith respect to I? A) :ero ) first C) second ") third Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder 2+) Hiven the follo#ing hypothetical reaction$ 2 I0 g g ) G0 g ) H0 g g ) 3 products. f the rate la# is$ 'ate / k DIE DIE2DGE18 #hat is the overall order of reaction? A) :ero ) first C) second ") third Ans#er$ "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder 2-) %he decomposition of ammonia to nitrogen and hydrogen on a tungsten filament at 9>>BC 9 >>BC is independent of the concentration of ammonia at high pressures of ammonia. What is the order of the reaction #ith respect to ammonia? A) :ero ) first C) second ") third Ans#er$ A "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder 26) Cerium0J) ion reacts #ith thallium0) ion in a onestep reaction sho#n belo#$ 2 Ce-0aq) aq) %l0aq) aq) 3 2 Ce+0aq) aq) %l+0aq). aq). f the rate la# is$ 'ate / k DCe DCe-E2D%lE8 #hat is the overall order of the reaction? A) first ) second C) third ") fourth Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder
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27) What is the overall reaction order for the reaction that has the rate la#$ 'ate / k D, D,2ED@E2? A) :ero order ) first order C) second order ") third order Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder Algo. ption$ algorithmic 24) odide and hypochlorite ion react in a*ueous solution according to the reaction belo#$ Cl 3 Cl f the concentration of , in the solution is doubled8 the rate of the reaction is halved. What is the order of the reaction #ith respect to Cl? A) 2 ) 1 C) 1 ") 2 Ans#er$ "iff$ + %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder 29) Chlorine reacts #ith chloroform according to the reaction given belo#$ Cl2 C,Cl+ 3 CCl- ,Cl When the initial concentration of Cl2 is doubled the reaction rate increases by b y a factor of 1.-1. What is the order of the reaction #ith respect to Cl 2? A) 1<2 ) 1 C) 1<2 ") 2 Ans#er$ C "iff$ + %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder 2) f the units for rate are M s 18 #hat are the units for the rate constant8 !8 if the overall order of the reaction is three? A) s1 ) M2 s1 C) M1 s1 ") M2 s1 Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder
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+>) Ksing the method of initial rates for the reaction A 3 8 if the initial concentration of A is doubled and the rate of reaction *uadruples8 #hat is the order of reaction #ith respect to A? A) :eroth ) first C) second ") fourth Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.+ "etermining a 'ate a#$ a#$ %he Method of nitial nitial 'ates +1) %he follo#ing set of data #as obtained b y the method of initial rates for the reaction$ 2 ,gCl20aq) aq) C2-20aq) aq) 3 2 Cl0aq) aq) 2 C20 g g ) ,g2Cl20 s) s) What is the rate la# for the reaction?
A) 'ate / k D,gCl D,gCl2EDC2-2E2 ) 'ate / k D,gCl D,gCl2EDC2-2E1 C) 'ate / k D,gCl D,gCl2E2DC2-2E ") 'ate / k D,gCl D,gCl2EDC2-2E2 Ans#er$ " "iff$ + %opic$ %opic$ &ection 12.+ "etermining a 'ate a#$ a#$ %he Method of nitial nitial 'ates
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+2) %he follo#ing set of data #as obtained b y the method of initial rates for the reaction$ 2 ,gCl20aq) aq) C2-20aq) aq) 3 2 Cl0aq) aq) 2 C20 g g ) ,g2Cl20 s) s) What is the value of the rate constant8 k ?
A) 1.- 1>9 14 16 1- 1- s1 ) -.- 1>- s1 C) 1.9 1>- s1 ") none of these Ans#er$ "iff$ + %opic$ %opic$ &ection 12.+ "etermining a 'ate a#$ a#$ %he Method of nitial nitial 'ates +6) %he follo#ing set of data #as obtained b y the method of initial rates for the reaction$ r+0aq) aq) 6 r 0aq) aq) 7 ,0aq) aq) 3 + r 20aq) aq) + ,20l 0l ). ). What is the rate la# for the reaction?
A) 'ate / k Dr Dr+EDr ED,E) 'ate / k Dr Dr+EDr ED,EC) 'ate / k Dr Dr+EDr ED,E2 ") 'ate / k Dr Dr+EDr ED,E2 Ans#er$ " "iff$ %opic$ %opic$ &ection 12.+ "etermining a 'ate a#$ a#$ %he Method of nitial nitial 'ates
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+7) %he follo#ing set of data #as obtained b y the method of initial rates for the reaction$ r+0aq) aq) 6 r 0aq) aq) 7 ,0aq) aq) 3 + r 20aq) aq) + ,20l 0l ). ). Calculate the initial rate #hen r+ is >.+> M8 r is >.>6> M8 and , is >.16 M.
A) 7.1 1>6 M+ M2 M2 M.16 M and is >.16 M?
A) -.1> 1>7 M s1 ) 9.1> 1>+ M s1 C) 1.22 1>2 M s1 ") 6.-> 1>2 M s1 Ans#er$ "iff$ %opic$ %opic$ &ection 12.+ "etermining a 'ate a#$ a#$ %he Method of nitial nitial 'ates +) %he firstorder decomposition of hydrogen pero5ide occurs according to the e*uation 2 ,220aq) aq) 3 2 ,20l 0l ) 20 g g ) Ksing data from a concentrationtime study of this reaction8 #hich plot #ill produce a straight line? A) D,22E versus time ) D,22E2 versus time C) 1) Gor a particular firstorder reaction8 it ta!es -9 minutes for the concentration of the reactant to decrease to 26 of its initial value. What is the v alue for rate constant 0in s1) for the reaction? A) 1.> 1>- s1 ) -.9 1>- s1 C) 7.> 1>+ s1 ") 2. 1>2 s1 Ans#er$ "iff$ + %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# Algo. ption$ algorithmic
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-1) %he firstorder reaction8 &2Cl2 3 &2 Cl28 has a rate constant e*ual to 2.2> 1>6 s1 at 6+ =. What percentage of the initial amount of &2Cl2 #ill remain after 2.>> hours? A) 1.>> ) 1-.4 C) 14.1 ") 96.- Ans#er$ " "iff$ + %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# Algo. ption$ algorithmic -2) %he firstorder reaction8 2 @20 g g ) 3 2 @20 g g ) 20 g g )8 )8 has a rate constant e*ual to >.47 s1 at 1>>> =. ,o# long #ill it ta!e for the concentration of @2 to decrease to -2 of its initial concentration? A) >.99 s ) 1.1 s C) 1.9 s ") 2.- s Ans#er$ "iff$ + %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# Algo. ption$ algorithmic -+) %he isomeri:ation reaction8 C,+ @C 3 C,+C@8 is first order and the rate constant is e*ual to >.-7 s1 at 7>> =. What is the concentration concen tration of C,+ @C after >.2> minutes if the initial concentration is >.1> M? A) -.> 5 1>- M ) .1 5 1>- M C) -.> 5 1>2 M ") .1 5 1>2 M Ans#er$ A "iff$ %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# Algo. ption$ algorithmic
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--) %he follo#ing reaction is first order$ C2,7 3 2 C,+. f the rate constant is e*ual to 6.6 1>- s1 at 1>>> =8 ho# ho # long #ill it ta!e for >.+6 mol of C2,7 in a 1.>> container to decrease to >.1> mol in the same container? A) 4.7 min ) +9 min C) 1>7 min ") 1+1 min Ans#er$ "iff$ %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# Algo. ption$ algorithmic -6) %he decomposition of cyclopropane8 #as observed at 6>>BC and its concentration #as monitored as a function of time. %he data set is given belo#. What is the order of the reaction #ith respect to cyclopropane?
A) :ero ) first C) second ") third Ans#er$ "iff$ 6 %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# -7) %he half life of the reaction sho#n belo# is found not to depend on the concentration of ,220aq). aq). 2 ,220aq) aq) 3 2 ,20l 0l ) 20 g g ) What is the order of this reaction? A) :eroth ) first C) second ") third Ans#er$ "iff$ 2 %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife
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-4) %he rate constant8 k 8 for a firstorder reaction is e*ual to -.2 1>- s1. What is the halflife for the reaction? A) 2. 1>- s ) 1.2 1>+ s C) 1.4 1>+ s ") 2.- 1>+ s Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife Algo. ption$ algorithmic -9) Acetaldehyde decomposes at 46> =$ C,+C, 3 C C,-. %he reaction is first order in acetaldehyde and the halflife of the reaction is found to be 6+> seconds. What is the rate constant for the reaction at this temperature? A) 2.4 5 1>+ s1 ) 1.+ 5 1>+ s1 C) 2.4 5 1>2 s1 ") 4.7 5 1>2 s1 Ans#er$ "iff$ 2 %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife -) %he firstorder reaction8 &2Cl2 3 &2 Cl28 has a halflife of 9.46 hours at 6+ =. ,o# long #ill it ta!e for the concentration of & 2Cl2 to fall to 12.6 of its initial value? A) >.176 hr ) +.22 hr C) 7.>7 hr ") 27.2 hr Ans#er$ " "iff$ + %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife Algo. ption$ algorithmic 6>) Gor the firstorder reaction8 2 @20 g g ) 3 2 @20 g g ) 20 g g )8 )8 #hat is the concentration of @2 after + halflives if >.16 mol of @ 2 is initially placed into in a 1.>> reaction vessel? A) .- 1>+ M ) 1. 1>2 M C) +.9 1>2 M ") 4.6 1>2 M Ans#er$ "iff$ + %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife Algo. ption$ algorithmic 1 Copyright © 2014 Pearson Education, Inc.
61) Gluorine19 is an isotope used in Nositron N ositron Imission %omography %omography 0NI%) to scan the brain. f a researcher has 1.6> Og of 19G8 ho# long before it decays to 1.> ng? %he halflife of 19G is 1>.9 minutes. A) 6.2 1>2 hr ) -.7 1>2 hr C) 1 hr ") 61 hr Ans#er$ C "iff$ + %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife 62) odine1+1 is one of the many radioactive isotopes resulting from nuclear bomb e5plosions. ,o# long #ould it ta!e for of the iodine1+1 produced a nuclear e5plosion to disappear? %he halflife of iodine1+1 is 9.>2 days. A) 6+.+ days ) 9>.2 days C) ->.4 days ") 9>2 days Ans#er$ A "iff$ + %opic$ %opic$ &ection 12.7 Girstrder Girstrder 'eactions$ 'adioactive "ecay 6+) 'ecent nuclear reactor accidents have contaminated contaminated many soils around the #orld. ne of the isotopes deposited in soils is cesium1+4. f the activity must fall by a factor of for contamination to disappear8 ho# long #ill it ta!e before uncontaminated crops may be gro#n in these soils? %he halflife of cesium1+4 cesium1+4 is +>.2 years. A) +>1 years ) >.2+ year C) ++.1 years ") >.>+ year Ans#er$ A "iff$ + %opic$ %opic$ &ection 12.7 Girstrder Girstrder 'eactions$ 'adioactive "ecay 6-) A plot of 1 ) 1 C) 2 ") + Ans#er$ C "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions 66) n a*ueous solution8 hypobromite ion8 r8 reacts to produce bromate ion8 r+8 and 1! Copyright © 2014 Pearson Education, Inc.
bromide ion8 r 8 according to the follo#ing chemical che mical e*uation. + r0aq) aq) 3 r+0aq) aq) 2 r 0aq) aq) A plot of 1.>67 M1s1. f the initial initial concentration of r is >.9> M8 ho# long #ill it ta!e onehalf of the r ion to react? A) -.6 1>2 s ) 4.1 s C) 12 s ") 22 s Ans#er$ " "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions Algo. ption$ algorithmic 67) %he secondorder reaction8 2 Mn0C)6 3 Mn20C)1> has a rate constant e*ual to +.> 1> M1s1 at 26BC. f the initial concentration of Mn0C)6 is 1.> 1> 6 M8 ho# long #ill it ta!e for >. of the reactant to disappear? A) +.+ 1>17 s ) +.4 1>16 s C) +.> 1>- s ") +.> 1>+ s Ans#er$ C "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions Algo. ption$ algorithmic 64) @itrogen dio5ide decomposes at +>>BC via a secondorder process to produce nitrogen mono5ide and o5ygen according to the follo#ing chemical e*uation. 2 @20 g g ) 3 2 @0 g ) 20 g g ). ). A sample of @20 g g ) is initially placed in a 2.6> reaction vessel at +>>BC. f the h alflife and the rate constant at +>>BC are 11 seconds and >.6- M1 s18 respectively8 ho# many moles of @2 #ere in the original sample? A) >.14 mol ) >.-2 mol C) 6. mol ") 16 mol Ans#er$ "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions Algo. ption$ algorithmic
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69) ,ydrogen iodide decomposes at 9>> = via a secondorder process to produce hydrogen and iodine according to the follo#ing chemical e*uation. 2 ,0 g g ) 3 ,20 g g ) 20 g g ) At 9>> = it ta!es 1-2 seconds for the initial concentration of , to decrease from 7.46 1>2 M to +.6> 1>2 M. What is the rate constant for the reaction at this temperature? A) 6.12 1>- M1s1 ) .7 1>2 M1s1 C) 1>.+ M1s1 ") 1.6 1>+ M1s1 Ans#er$ "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions Algo. ption$ algorithmic 6) %he reaction$ 2 , 3 ,2 28 is second order and the rate constant at 9>> = is .4> 1>2 M1 s1. ,o# long #ill it ta!e for 9.>> 1> 2 mol< of , to decrease to onefourth of its initial concentration? A) >.71 s ) 12- s C) +94 s ") -2 s Ans#er$ C "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions 7>) Which statement belo# regarding the halflife of a secondorder reaction is true? A) Iach halflife is half as long as the preceding one. ) Iach halflife is t#ice as long as the preceding one. C) Iach halflife is four times as long as the preceding one. ") %he length of the halflife remains unchanged throughout the course of the reaction. Ans#er$ "iff$ 2 %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions 71) Gor the hypothetical second order reaction$ A 3 products8 the general rate la# is$ rate / k DAE DAE2. ,o# long is the third halflife of the reaction if DAE> is >.>9> M and the first halflife is 22 minutes? A) >.64 min ) 1.4 min C) 4.+ min ") 99 min Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions 21 Copyright © 2014 Pearson Education, Inc.
72) f the units for rate are M s 18 #hat are the units for the rate constant8 k 8 for a :erothorder reaction? A) s1 ) M1 C) M s1 ") M1 s1 Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.9 Perothrder Perothrder 'eactions 7+) Gor the :erothorder reaction$ C 3 products8 DCE<t DCE<t / / k 8 #hich of the follo#ing graphs #ould be e5pected to give a straight line? A) DCE vs. t ) lnDCE vs. t C) 1) A mechanism for a naturally occurring reaction that destroys o:one is$ &tep 1$ +0 g g ) ,0 g g ) 3 ,20 g g ) 20 g g ) &tep 2$ ,20 g g ) 0 g g ) 3 ,0 g ) 20 g g ) What is the molecularity of the overall reaction? A) unimolecular ) bimolecular C) none of these because molecularity is the difference of the e5ponents in the rate la# ") none of these because molecularity only refers to elementary steps Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.11 'eaction Mechanisms 41) A threestep mechanism has been suggested for the formation of o f carbonyl chloride$ &tep 1$ Cl2 3 2 Cl &tep 2$ Cl C 3 CCl &tep +$ CCl Cl2 3 CCl2 Cl Which species is an intermediate in the mechanism? A) Cl ) C C) CCl ") CCl2 Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.11 'eaction Mechanisms 42) %he slo#est step in a reaction mechanism is called the RRRRRRRR step. A) activation ) elementary C) rate la# ") ratedetermining Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.1+ 'ate a#s for verall 'eactions 4+) Which of the follo#ing statements are true about reaction mechanisms? . A rate rate la# can be #ritte #ritten n from the the moleculari molecularity ty of the the slo#est slo#est element elementary ary step. step. . %he final final rate rate la# la# can include include intermediat intermediates. es. . %he rate of the reaction is dependent on the fastest step step in the mechanism. J. J. A mechanism mechanism can never be proven to be the correct path#ay path#ay for a reaction. A) 8 8 ) 8 J C) 8 ") 8 J Ans#er$ " "iff$ + %opic$ %opic$ &ection 12.1+ 'ate a#s for verall 'eactions 24 Copyright © 2014 Pearson Education, Inc.
4-) Which general rate la# belo# corresponds to an elementary bimolecular reaction? A) 'ate / k DAE DAE ) 'ate / k DAEDEDCE DAEDEDCE C) 'ate / k DAE DAE2DE ") 'ate / k DAEDE DAEDE Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.12 'eaction a#s for Ilementary 'eactions 46) What is the rate la# for the elementary reaction sho#n belo#? 2 , 3 ,2 2 A) 'ate / k D,E D,E ) 'ate / k D,E D,E2 C) 'ate / k D, D,2ED2E ") 'ate / k D, D,2ED2E) What factor affects the rate of a chemical reaction? A) collision fre*uency ) fraction of collisions #ith sufficient energy C) orientation of molecules ") all of the above Ans#er$ " "iff$ + %opic$ %opic$ &ection 12. 'eaction 'ates and %emperature$ %emperature$ Collision %heory and the Arrhenius I*uation 91) A gas molecule at 29 = and 1 atm pressure undergoes a collision #ith another gas molecule appro5imately every RRRRRRRR seconds. A) 1>16 ) 1> C) 1>7 ") 1>+ Ans#er$ "iff$ 2 %opic$ %opic$ &ection 12. 'eaction 'ates and %emperature$ %emperature$ Collision %heory and the Arrhenius I*uation 92) %he fraction of collisions #ith sufficient energy to react is e*ual to A) A A) A ) E ) E a C) eIa<'% ") p ") p Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12. 'eaction 'ates and %emperature$ %emperature$ Collision %heory and the Arrhenius I*uation 9+) What fraction of collisions #ill have sufficient energy to react for a gas #hose activation energy is 79 !U12 ) 2.4 1>2 C) >.7 ") 9.+ 1>11 Ans#er$ A "iff$ + %opic$ %opic$ &ection 12. 'eaction 'ates and %emperature$ %emperature$ Collision %heory and the Arrhenius I*uation
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9-) When the temperature of a gas #hose activation energy is 66 !U> = to +2> =8 the fraction of collisions #ith sufficient energy to react A) decreases by a factor of 2. ) decreases by a factor of -. C) increases by a factor of 2. ") increases by a factor of -. Ans#er$ " "iff$ %opic$ %opic$ &ection 12. 'eaction 'ates and %emperature$ %emperature$ Collision %heory and the Arrhenius I*uation 96) A common rule of thumb in organic chemistry is that increasing the temperature of a reaction at room temperature by 1>BC doubles the rate. Calculate Ia for a reaction that follo#s this rule of thumb. Assume room temperature is 26BC. A) >.647 !U ) 12.2 !U C) +9.- !U ") 62. !U Ans#er$ " "iff$ %opic$ %opic$ &ection 12.1> Ksing the Arrhenius I*uation I*uation 97) Consider a bimolecular reaction in the gas phase. Which one of the follo#ing changes in condition #ill not cause an increase in the rate of the reaction? A) add a catalyst ) increase the temperature at constant volume C) increase the volume at constant temperature ") All of the above #ill increase the rate of reaction. Ans#er$ C "iff$ + %opic$ %opic$ &ection 12.1- Catalysis 94) Which part of the Arrhenius e*uation contains a term #hich measures the number of molecules that have the correct orientation for reaction? A) activation energy ) eIa<'% C) fre*uency factor ") none of these Ans#er$ C "iff$ + %opic$ %opic$ &ection 12. 'eaction 'ates and %emperature$ %emperature$ Collision %heory and the Arrhenius I*uation
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99) %he reaction for the decomposition of dinitrogen mono5ide gas to form o5ygen radicals is$ . f the rate constant is +.>- 1>2 s1 and the fre*uency factor is 9.>> 1>11 s18 #hat is the activation energy for the firstorder reaction at 4>>BC? A) >.272 !U !U !U !U 1>11 s18 #hat is the rate constant for the firstorder reaction at 1>>> =? A) 1.1 1>+ s1 ) 4.> 1>2 s1 C) 1.7 1>1+ s1 ") .1 1>2- s1 Ans#er$ "iff$ %opic$ %opic$ &ection 12. 'eaction 'ates and %emperature$ %emperature$ Collision %heory and the Arrhenius I*uation >) %he a*uation of tris018 1>phenanthroline)iron0) in acid solution ta!es place according to the e*uation$ Ge0phen)+2 + ,+ + ,2 3 Ge0,2)72 + phen, f the activation energy is 127 !U14 s18 at #hat temperature is the rate constant e*ual to +.7+ 1>+ s1 for the firstorder reaction? A) >BC ) +7BC C) 6>BC ") -BC Ans#er$ C "iff$ %opic$ %opic$ &ection 12.1> Ksing the Arrhenius I*uation I*uation
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1) %he a*uation of tris018 1>phenanthroline)iron0) in acid solution ta!es place according to the e*uation$ Ge0phen)+2 + ,+ + ,2 3 Ge0,2)72 + phen, f the activation energy8 Ia8 is 127 !UBC is .9 1>+ min18 #hat is the fre*uency fre*uenc y factor8 A? A) 2.- 1>2- min1 ) 2.- 1>2> min1 C) 6.2 1>1 min1 ") 6.2 1>2+ min1 Ans#er$ C "iff$ %opic$ %opic$ &ection 12. 'eaction 'ates and %emperature$ %emperature$ Collision %heory and the Arrhenius I*uation 2) %he a*uation of tris018 1>phenanthroline)iron0) in acid solution ta!es place according to the e*uation$ Ge0phen)+2 + ,+ + ,2 3 Ge0,2)72 + phen,. f the activation energy8 Ia8 is 127 !UBC is .9 1>+ min18 #hat is the rate constant at 6>BC? A) -.- 1>- min1 ) 2.2 1>1 min1 C) -.7 1>> min1 ") 2.+ 1>+ min1 Ans#er$ "iff$ %opic$ %opic$ &ection 12.1> Ksing the Arrhenius I*uation I*uation Algo. ption$ algorithmic +) %he firstorder isomeri:ation reaction$ cyclopropane 3 propene8 has a rate co nstant of at -4>BC and What is the activation energy8 Ia8 for the reaction? A) -7 !U !U !U !U Ksing the Arrhenius I*uation I*uation
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-) %he firstorder isomeri:ation reaction$ cyclopropane 3 propene8 has a rate co nstant of at -4>BC and an activation energy of 27- !UBC ") 6->BC Ans#er$ " "iff$ %opic$ %opic$ &ection 12.1> Ksing the Arrhenius I*uation I*uation 6) %he decomposition of hydrogen pero5ide is given by the follo#ing reaction$ 2 ,220aq) aq) 3 2 ,20l 0l ) 20 g g ) n the presence of = the reaction is thought to occur by the follo#ing mechanism$ &tep 1$ ,22 3 ,2 &tep 2$ ,22 3 ,2 2 What is the role of in this mechanism? A) catalyst ) fre*uency factor C) intermediate ") transition state Ans#er$ A "iff$ 2 %opic$ %opic$ &ection 12.1- Catalysis 7) A mechanism for a naturally occurring reaction that destroys o:one is$ &tep 1$ +0 g g ) ,0 g g ) 3 ,20 g g ) 20 g g ) &tep 2$ ,20 g g ) 0 g g ) 3 ,0 g ) 20 g g ) Which species is a catalyst? A) , ) ,2 C) ") + Ans#er$ A "iff$ 2 %opic$ %opic$ &ection 12.1- Catalysis
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4) %he decomposition of o:one in the stratosphere can occur by the follo#ing t#ostep mechanism$ r + 3 r 2 r 3 r 2 Which species is a catalyst in this mechanism? A) r ) r C) ") + Ans#er$ A "iff$ 2 %opic$ %opic$ &ection 12.1- Catalysis 9) Which of the follo#ing does not affect the rate of a bimolecular reaction? A) concentrations of reactants ) presence of a catalyst C) temperature ") All of the above affect the rate. Ans#er$ " "iff$ 1 %opic$ %opic$ &ection 12.1- Catalysis ) An a*ueous reaction occurs by a t#ostep mechanism8 sho#n belo#. &tep 1$ A2S2 T 3 A2S ST &tep 2$ A2S2 ST 3 A2S S2 T What is the catalyst in this reaction? A) A2S ) S2 C) ST ") T Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.1- Catalysis 1>>) A mechanism mechanism for a naturally n aturally occurring reaction that destroys o:one is$ &tep 1$ +0 g g ) ,0 g ) 3 ,20 g g ) 20 g g ) &tep 2$ ,20 g g ) 0 g ) 3 ,0 g ) 20 g g ) Which species is a catalyst and #hat type of catalysis is occurring? A) ,8 homogeneous ) ,8 heterogeneous C) ,28 homogeneous ") ,28 heterogeneous Ans#er$ A "iff$ + %opic$ %opic$ &ection 12.16 ,omogeneous and ,eterogeneous Catalysts 32 Copyright © 2014 Pearson Education, Inc.
1>1) %he ,aber process is the synthesis of ammonia gas from hydrogen and nitrogen on a hot metal surface. What is the catalyst and #hat type of ca talysis is occurring? A) ,28 homogeneous ) @28 homogeneous C) @,+8 homogeneous ") metal surface8 heterogeneous Ans#er$ " "iff$ + %opic$ %opic$ &ection 12.16 ,omogeneous and ,eterogeneous Catalysts &ho#n is a concentration versus time plot for a reaction involving gases A8 8 and C.
1>2) Which e*uation best represents the reaction? A) -A0 g g ) 3 0 g g ) 2C0 g ) ) -A0 g g ) 0 g ) 3 2C0 g ) C) 2C0 g g ) 3 -A0 g g ) 0 g ) ") 2C0 g g ) 0 g ) 3 -A0 g ) Ans#er$ C "iff$ 2 %opic$ %opic$ Conceptual Nroblems
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1>+) ver the time interval +>> to ->> seconds8 the rate of reaction #ith respect to A is DAE< DAE<t t / +.4 1>6 M6 M 6 M 7 M 6 M 6 M6 M 6 M-) ver the time interval +>> to ->> seconds8 the rate of reaction #ith respect to A is DAE< DAE<t t / +.4 1>6 M6 M 6 M 7 M 6 M 6 M6 M 6 M6) ver the time interval +>> to ->> seconds8 the rate of reaction #ith respect to A is DAE< DAE<t t / +.4 1>6 M> to 9>> seconds? A) > M6 M6 M6 M7) ver the time interval +>> to ->> seconds8 the rate of reaction #ith respect to A is DAE< DAE<t t / +.4 1>6 M to 1>> seconds? A) > M6 M6 M6 M4) What is the order of reaction #ith respect to A2? A) > ) 1 C) 2 ") + Ans#er$ A "iff$ + %opic$ %opic$ Conceptual Nroblems 1>9) What is the order of reaction #ith respect to 2? A) > ) 1 C) 2 ") + Ans#er$ C "iff$ + %opic$ %opic$ Conceptual Nroblems 1>) What is the overall order of reaction? A) > ) 1 C) 2 ") + Ans#er$ C "iff$ + %opic$ %opic$ Conceptual Nroblems 11>) What is the rate la# for this reaction? A) 'ate / k DA DA2E2 ) 'ate / k D D2E2 C) 'ate / k DA DA2ED2E ") 'ate / k DA DA2E2D2E2 Ans#er$ "iff$ + %opic$ %opic$ Conceptual Nroblems 35 Copyright © 2014 Pearson Education, Inc.
111) 111) %he follo#ing reaction is first order in A and first order in $ A 3 Nroducts 'ate / k DAEDE DAEDE What is the initial rate of this reaction in vessel 0b) relative to the initial rate of this reaction in vessel 0a)? Iach vessel has the same volume. vo lume. &haded spheres represent A molecules8 and unshaded spheres represent molecules present at the beginning of the reaction.
A) rate in vessel 0b)) Consider the firstorder reaction A 3 in #hich A molecules 0unshaded spheres) are converted to molecules 0shaded spheres). Hiven the follo#ing pictures at t / / > seconds and t / / 1>> seconds8 #hich picture represents the n umber of A and molecules remaining at +>> seconds?
A) picture a) ) picture b) C) picture c) ") picture d) Ans#er$ C "iff$ + %opic$ %opic$ Conceptual Nroblems 40 Copyright © 2014 Pearson Education, Inc.
121) Consider the firstorder reaction A 3 in #hich A molecules 0unshaded spheres) are converted to molecules 0shaded spheres). Hiven the follo#ing pictures at t / / > seconds and t / / 1>> seconds8 #hich picture represents the n umber of A and molecules remaining at 2>> seconds?
A) picture a) ) picture b) C) picture c) ") picture d) Ans#er$ C "iff$ + %opic$ %opic$ Conceptual Nroblems 122) Consider the firstorder decomposition of A molecules 0shaded spheres) in t#o vessels of e*ual volume. What is the halflife of decomposition in vessel 0b) relative to the halflife of decomposition in vessel 0a)?
A) halflife in vessel 0b) ) 1<2 C) 1 ") 2 Ans#er$ " "iff$ %opic$ %opic$ Conceptual Nroblems 12) What is the time re*uired to achieve the molecular mi5ture in dra#ing 0d)? A) - min ) 6 min C) 4 min ") 9 min Ans#er$ C "iff$ 1 %opic$ %opic$ Conceptual Nroblems
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1+>) Which of the elementary reactions sho#n above has a molecularity of one? A) elementary reaction 0a) ) elementary reaction 0b) C) elementary reaction 0c) ") elementary reactions 0a)8 0b)8 and 0c) Ans#er$ "iff$ 1 %opic$ %opic$ Conceptual Nroblems 1+1) Which of the elementary reactions sho#n above has a molecularity of t#o? A) elementary reaction 0a) ) elementary reaction 0b) C) elementary reaction 0c) ") elementary reactions 0a)8 0b)8 and 0c) Ans#er$ A "iff$ 1 %opic$ %opic$ Conceptual Nroblems 1+2) Which of the elementary reactions sho#n above has a molecularity of three? A) elementary reaction 0a) ) elementary reaction 0b) C) elementary reaction 0c) ") elementary reactions 0a)8 0b)8 and 0c) Ans#er$ C "iff$ 1 %opic$ %opic$ Conceptual Nroblems Consider a reaction that occurs by the follo#ing onestep mechanism$ A2 2 3 2 A %he potential energy profile for this reaction is sho#n belo#.
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1++) What is the species present at reaction stage 1? A) an intermediate ) a product C) a reactant ") a transition state Ans#er$ C "iff$ 1 %opic$ %opic$ Conceptual Nroblems 1+-) What is the species present at reaction stage 2? A) an intermediate ) a product C) a reactant ") a transition state Ans#er$ " "iff$ 1 %opic$ %opic$ Conceptual Nroblems 1+6) What is the species present at reaction stage +? A) an intermediate ) a product C) a reactant ") a transition state Ans#er$ "iff$ 1 %opic$ %opic$ Conceptual Nroblems
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1+7) %he activation energy for the for#ard reaction is given by the difference in energy bet#een #hich t#o reaction stages? A) reaction stage 2 V reaction stage 1 ) reaction stage 2 V reaction stage + C) reaction stage 1 V reaction stage + ") reaction stage + V reaction stage 1 Ans#er$ A "iff$ 1 %opic$ %opic$ Conceptual Nroblems 1+4) %he energy of reaction8 I8 is given by the difference in energy bet#een #hich t#o reaction stages? A) reaction stage 2 V reaction stage 1 ) reaction stage 2 V reaction stage + C) reaction stage 1 V reaction stage + ") reaction stage + V reaction stage 1 Ans#er$ " "iff$ 1 %opic$ %opic$ Conceptual Nroblems
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Consider a reaction that occurs by the follo#ing mechanism$ A C 3 AC AC " 3 A C" %he potential energy profile for this reaction is sho#n belo#.
1+9) %ransition states occur at #hich reaction stages? A) reaction stages 1 and 6 ) reaction stages 28 +8 and C) reaction stages 2 and ") reaction stage + Ans#er$ C "iff$ + %opic$ %opic$ Conceptual Nroblems 1+) ntermediates occur at #hich reaction stages? A) reaction stages 1 and 6 ) reaction stages 28 +8 and C) reaction stages 2 and ") reaction stage + Ans#er$ " "iff$ %opic$ %opic$ Conceptual Nroblems
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1->) What is the activation energy for the formation of o:one? A) 1- !U ) +2 !U C) ->7 !U ") none of these Ans#er$ C "iff$ + %opic$ %opic$ Conceptual Nroblems 1-1) What is the activation energy for the destruction of o:one? A) 1- !U ) +2 !U C) ->7 !U ") none of these Ans#er$ A "iff$ %opic$ %opic$ Conceptual Nroblems
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12.2 Algorithmic Algorithmic Questions 1) %he reaction that occurs in a reathaly:er8 a device u sed to determine the alcohol level in a person;s bloodstream8 is given belo#. f the rate of appearance of Cr 20&-)+ is 1.7- mol.6-4 mol mol mol.9>> mol mol mol mol.67> mol.1-> mol.29> mol> mol.46> mol mol> mol mol>? %he rate #ill A) decrease by a factor of 1<26.>. ) decrease by a factor of 1<6.>>. C) increase by a factor of 6.>>. ") increase by a factor of 26.>. Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder Algo. ption$ algorithmic 7) Gor a reaction that follo#s the general rate la#8 'ate / k DAEDE DAEDE28 #hat #ill happen to the rate of reaction if the concentration concentration of is increased by a factor of +.>>? %he rate #ill A) decrease by a factor of 1<.>>. ) decrease by a factor of 1<+.>>. C) increase by a factor of +.>>. ") increase by a factor of .>>. Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder Algo. ption$ algorithmic 4) What is the overall reaction order for the reaction that has the rate la#$ 'ate / k D D2E D@ E2? A) :ero order ) first order C) second order ") third order Ans#er$ " "iff$ 2 %opic$ %opic$ &ection 12.2 'ate a#s and 'eaction rder Algo. ption$ algorithmic
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9) Gor a particular firstorder reaction8 it ta!es 2- minutes for the con centration of the reactant to decrease to 26 of its initial value. What is the value for rate constant 0in s1) for the reaction? A) 2.> 1>- s1 ) .7 1>- s1 C) 1.2 1>2 s1 ") 6.9 1>2 s1 Ans#er$ "iff$ + %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# Algo. ption$ algorithmic ) %he firstorder reaction8 &2Cl2 3 &2 Cl28 has a rate constant e*ual to 2.2> 1>6 s1 at 6+ =. What percentage of the initial amount &2Cl2 #ill remain after 7.>> hours? A) 1.>> ) +4.9 C) ->.2 ") 72.2 Ans#er$ " "iff$ + %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# Algo. ption$ algorithmic 1>) %he firstorder reaction8 2 @20 g g ) 3 2 @20 g g ) 20 g g )8 )8 has a rate constant e*ual to >.47 s1 at 1>>> =. ,o# long #ill it ta!e for the concentration of @2 to decrease to 12 of its initial concentration? A) >.72 s ) 2.9 s C) 7.+ s ") 9.- s Ans#er$ "iff$ + %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# Algo. ption$ algorithmic
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11) %he isomeri:ation reaction8 C,+ @C 3 C,+C@8 is first order and the rate constant is e*ual to >.-7 s1 at 7>> =. What is the concentration concen tration of C,+ @C after >.2> minutes if the initial concentration is >.+> M? A) 1.2 1>+ M ) 2.4 1>+ M C) 1.2 1>1 M ") 2.4 1>1 M Ans#er$ A "iff$ + %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# Algo. ption$ algorithmic 12) %he follo#ing reaction is first order8 C2,7 3 2 C,+. f the rate constant is e*ual to 6.6 1>- s1 at 1>>> =8 ho# ho # long #ill it ta!e for >.+6 mol of C2,7 in a 1.>> container to decrease to >.2> mol in the same container? A) -.6 min ) 14 min C) 6+ min ") 76 min Ans#er$ "iff$ %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife Algo. ption$ algorithmic 1+) %he rate constant8 k 8 for a firstorder reaction is e*ual to -.2 1>- s1. What is the halflife for the reaction? A) 2. 1>- s ) 1.2 1>+ s C) 1.4 1>+ s ") 2.- 1>+ s Ans#er$ C "iff$ 2 %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife Algo. ption$ algorithmic
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1-) %he firstorder reaction8 &2Cl2 3 &2 Cl28 has a halflife of 9.46 hours at 6+ =. ,o# long #ill it ta!e for the concentration of & 2Cl2 to fall to 17.6 of its initial value? A) >.1-+ hr ) 2.29 hr C) 7. hr ") 22.4 hr Ans#er$ " "iff$ + %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife Algo. ption$ algorithmic 16) Gor the firstorder reaction8 2 @20 g g ) 3 2 @20 g g ) 20 g g )8 )8 #hat is the concentration of @2 after + halflives if mol of @2 is initially placed into a 1.>> reaction vessel? A) 1.7 1>2 M ) +.1 1>2 M C) 7.2 1>2 M ") 1.2 1>1 M Ans#er$ "iff$ + %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife Algo. ption$ algorithmic 17) Carbon1-8 #hich is present in all living tissue8 radioactively decays via a firstorder process. A onegram sample of #ood ta!en from a living tree gives a rate for carbon1- decay of 1+.7 counts per minute. f the halflife halflife for carbon1- is 6416 years8 years8 ho# old is a #ood sample sample that gives a rate for carbon1- decay of 11. counts per minute? A) 6.+ 1>2 yr ) 4.7 1>2 yr C) 1.1 1>+ yr ") .- 1>+ yr Ans#er$ C "iff$ 6 %opic$ %opic$ &ection 12.7 Girstrder Girstrder 'eactions$ 'adioactive "ecay Algo. ption$ algorithmic
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14) n a*ueous solution8 hypobromite ion8 r8 reacts to produce bromate ion8 r+8 and bromide ion8 r 8 according to the follo#ing chemical che mical e*uation. A plot of 1.>67 M1s1. f the initial concentration of r is >.9> M8 ho# long #ill it ta!e onehalf of the r ion to react? A) -.6 1>2 s ) 4.1 s C) 12 s ") 22 s Ans#er$ " "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions Algo. ption$ algorithmic 19) %he secondorder reaction 2 Mn0C)6 3 Mn20C)1>8 has a rate constant e*ual to +.> 1> M1 s1 at 26BC. f the initial initial concentration of Mn0C)6 is 2.> 1>6 M8 ho# long #ill it ta!e for >. of the reactant to disappear? A) 7.4 1>17 s ) 4.- 1>16 s C) 1.6 1>- s ") 7.> 1>+ s Ans#er$ C "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions Algo. ption$ algorithmic 1) @itrogen dio5ide decomposes at +>>BC via a secondorder process to produce nitrogen mono5ide and o5ygen according to the follo#ing chemical e*uation. 2 @20 g g ) 3 2 @0 g ) 20 g g ). ). A sample of @20 g g ) is initially placed in a 2.6> reaction vessel at +>>BC. f the h alflife and the rate constant at +>>BC are 11 seconds and >.6- M1 s18 respectively8 ho# many moles of @2 #ere in the original sample? A) >.14 mol ) >.-2 mol C) 6. mol ") 16 mol Ans#er$ "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions Algo. ption$ algorithmic
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2>) ,ydrogen iodide decomposes at 9>> = via a secondorder process to produce hydrogen and iodine according to the follo#ing chemical e*uation. 2,0 g g ) 3 ,20 g g ) 20 g g ) At 9>> = it ta!es 1-2 seconds for the initial concentration of , to decrease from 7.46 1>2 M to +.6> 1>2 M. What is the rate constant for the reaction at this temperature? A) 6.12 1>- M1s1 ) .7 1>2 M1s1 C) 1>.+ M1s1 ") 1.6 1>+ M1s1 Ans#er$ "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions Algo. ption$ algorithmic 21) %he activation for the follo#ing reaction is 19> !U2BC 2>2BC is -.1+ 1 8 #hat #hat is the rate rate constan constantt at 244BC? 244BC? A) 2.1> 1 ) 1.77 1 C) 6.+ ") +. Ans#er$ A "iff$ %opic$ %opic$ &ection 12.1> Ksing the Arrhenius I*uation I*uation Algo. ption$ algorithmic 22) %he a*uation of tris0181>phenanthroline)iron0) in acid solution ta!es place according to the e*uation$ Ge0phen)+2 + ,+ + ,2 3 Ge0,2)72 + phen,. f the activation energy8 Ia8 is 127 !UBC is .9 1>+ min18 #hat is the rate constant at +6BC? A) -.- 1>+ min1 ) 2.2 1>2 min1 C) -.6 1>1 min1 ") 2.+ 1>2 min1 Ans#er$ "iff$ %opic$ %opic$ &ection 12.1> Ksing the Arrhenius I*uation I*uation Algo. ption$ algorithmic
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12.+ &hort Ans#er Questions 1) Gor the reaction sho#n belo#8 belo#8 if the the rate of formation of 2 is 7.> 1> F7 M F6 M>BC decomposition of @20 g g ) occurs #ith a rate la#$ 'ate / F !D@2E x. f the initial rate of decomposition is +.2 1> F6 M 1> F+ M and the initial rate of decomposition is 9.> 1> F7 M 1> F+ M8 then the order of reaction #ith respect to @28 x / x / RRRRRRRR. Ans#er$ 2 "iff$ + %opic$ %opic$ &ection 12.+ "etermining a 'ate a#$ a#$ %he Method of nitial nitial 'ates -) %he decomposition of hydrogen pero5ide occu rs according to the e*uation 2 ,220aq) aq) 3 2 ,20l 0l ) 20 g g ) A concentrationtime concentrationtime study of this reaction produces a straight line #hen lnD,22E is plotted versus time. %herefore8 this is a RRRRRRRR order reaction. Ans#er$ first "iff$ 2 %opic$ %opic$ &ection 12.- Girstrder 'eactions$ 'eactions$ %he ntegrated 'ate 'ate a# 6) At 66B the decomposition of @26 is first order8 having a rate constant8 k / / 1.4 1> F+ s F1. f the initial concentration of @26 is 7.- 1> F+ M8 the number of halflives that are re*uired for the @26 concentration to fall to 2.> 1> F- M is RRRRRRRR8 and the amount of time re*uired is RRRRRRRR minutes. Ans#er$ 68 +"iff$ %opic$ %opic$ &ection 12.6 Girstrder Girstrder 'eactions$ ,alfife
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7) Carbon1- has a halflife halflife of 6416 years. Currently living organisms organisms decay at a rate of 16.+ disintegrations< min min per gram of carbon. f an archeological artifact has a carbon1- decay rate of 12.> disintegrations< min per gram of carbon8 the appro5imate age of the artifact is RRRRRRRR years old. Ans#er$ 2>>> "iff$ + %opic$ %opic$ &ection 12.7 Girstrder Girstrder 'eactions$ 'adioactive "ecay 4) At an elevated temperature the decomposition of a gaseous o5ide8 A2 occurs #ith a rate constant8 k / / >.6- M F1s F1. f the halflife halflife of this reaction reaction is 27 seconds #hen DA2E / 2.> 1> F+ M and -72 seconds #hen DA2E / -.> 1> F+ M8 this reaction is RRRRRRRR order. Ans#er$ second "iff$ + %opic$ %opic$ &ection 12.4 &econdrder 'eactions 'eactions 9) A gaseous compound8 C8 undergoes catalytic deco mposition at an initial rate of >.-6 M 1> F+ M and >.-6 M 1> F+ M. %herefore8 this is a RRRRRRRR order reaction. Ans#er$ :eroth "iff$ + %opic$ %opic$ &ection 12.9 Perothrder Perothrder 'eactions ) A reaction occurs by a t#ostep mechanism8 sho#n belo#. &tep &tep 1$ 1$ AS20 g g ) 3 AS0 g ) S0 g ) &tep &tep 2$ 2$ AS20 g g ) S0 g g ) 3 AS S20 g g ) %he intermediate in this reaction is RRRRRRRR8 and the molecularity of the second step is RRRRRRRR. Ans#er$ S0 g )8 )8 t#o "iff$ + %opic$ %opic$ &ection 12.11 'eaction Mechanisms 1>) A gaseous reaction occurs by a t#ostep mechanism8 mechan ism8 sho#n belo#. &tep 1$AS T2 3 AST2 &tep 2$AST2 AS 3 2 AST f the rate la# for this reaction is 'ate / k DASE DASE2DT2E8 the intermediate is RRRRRRRR8 and step RRRRRRRR is the ratedetermining step. Ans#er$ AST28 2 "iff$ + %opic$ %opic$ &ection 12.11 'eaction Mechanisms
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11) An An a*ueous reaction occurs by a t#ostep mechanism8 sho#n belo#. &tep &tep 1$ 1$ A2S2 T 3 A2S ST &tep &tep 2$ 2$ A2S2 ST 3 A2S S2 T n this reaction the intermediate is RRRRRRRR8 and the catalyst is RRRRRRRR. Ans#er$ ST8 T "iff$ + %opic$ %opic$ &ection 12.1- Catalysis
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