Deck 12: Chemical Kinetics

Question 1

Consider the following rate law: How are the exponents n and m determined?

A)by using the balanced chemical equation
B)by using the subscripts for the chemical formulas
C)by using the coefficients of the chemical formulas
D)by educated guess
E)by experiment

Answer 1

by experiment

Question 2

Consider the reaction: At a certain instant the initial rate of disappearance of the oxygen gas is X.What is the value of the appearance of water at the same instant?

A)1.2 X
B)1.1 X
C)0.86 X
D)0.58 X
E)cannot be determined from the data

Answer 2

0.86 X

Question 3

The following questions refer to the reaction between nitric oxide and hydrogen
2NO + H₂ $\to$ N₂O + H₂O


-What is the rate law for this reaction?

A)Rate = k[NO]
B)Rate = k[NO]²
C)Rate = k[NO]²[H₂]
D)Rate = k[NO][H₂]
E)Rate = k[N₂O][H₂O]

Answer 3

Rate = k[NO]²[H₂]

Question 4

A general reaction written as A + 2B $\to$ C + 2D is studied and yields the following data:


-What is the order of the reaction with respect to B?

A)0
B)1
C)2
D)3
E)4

Question 5

A general reaction written as A + 2B $\to$ C + 2D is studied and yields the following data:


-What is the order of the reaction with respect to A?

A)0
B)1
C)2
D)3
E)4

Question 6

Determine the initial rate of B consumption ( $\Delta$ [B]/ $\Delta$ t)for the first trial?

A)8.00 $\times$ 10^-3 mol/L·s
B)1.60 $\times$ 10^-2 mol/L·s
C)3.20 $\times$ 10^-2 mol/L·s
D)4.00 $\times$ 10^-3 mol/L·s
E)none of these (A-D)

Question 7

What is the numerical value of the rate constant?

A)0.053
B)1.19
C)2.37
D)5.63
E)none of these (A-D)

Question 8

Determine the initial rate of C production ( $\Delta$ [C]/ $\Delta$ t)if [A] = 0.200 M and [B] = 0.500 M.

A)4.74 $\times$ 10^-2 mol/L·s
B)2.37 $\times$ 10^-1 mol/L·s
C)1.19 $\times$ 10^-1 mol/L·s
D)8.23 $\times$ 10^-2 mol/L·s
E)none of these (A-D)

Question 9

The following initial rate data were found for the reaction
2MnO₄^- + 5H₂C₂O₄ + 6H⁺ $\to$ 2Mn²⁺ + 10CO₂ + 8H₂O


-What is the value of the rate constant?

A)2 $\times$ 10⁵ M.s^-1
B)2 $\times$ 10⁵ M^-2.s^-1
C)200 M^-1.s^-1
D)200 M^-2.s^-1
E)2 $\times$ 10^-4 M.s^-1

Question 10

Consider the following data concerning the equation:
H₂O₂ + 3I^- + 2H⁺ $\to$ I₃^- + 2H₂O



-The rate law for this reaction is

A)rate = k[H₂O₂][I^-][H⁺]
B)rate = k[H₂O₂]²[I^-]²[H⁺]²
C)rate = k[I^-][H⁺]
D)rate = k[H₂O₂][H⁺]
E)rate = k[H₂O₂][I^-]

Question 11

The average value for the rate constant k (without units)is

A)2710
B)2.74 $\times$ 10⁴
C)137
D)108
E)none of these

Question 12

Consider the reaction What is the ratio of the initial rate of the appearance of water to the initial rate of disappearance of oxygen?

A)1 : 1
B)2 : 1
C)1 : 2
D)2 : 2
E)3 : 2

Question 13

The following data were obtained for the reaction of NO with O₂.Concentrations are in molecules/cm³ and rates are in molecules/cm³.s.
What is the rate law?

A)Rate = k[NO][O₂]
B)Rate = k[NO][O₂]²
C)Rate = k[NO]²[O₂]
D)Rate = k[NO]²
E)Rate = k[NO]²[O₂]²

Question 14

The balanced equation for the reaction of bromate ion with bromide ion in acidic solution is given by: At a particular instant in time,the value of is mol/L s.What is the value of in the same units?

A)
B)
C)
D)
E)

Question 15

Consider the reaction X $\to$ Y + Z Which of the following is a possible rate law?

A)Rate = k[X]
B)Rate = k[Y]
C)Rate = k[Y][Z]
D)Rate = k[X][Y]
E)Rate = k[Z]

Question 16

The average rate of disappearance of ozone in the reaction is found to be atm over a certain interval of time.What is the rate of appearance of during this interval?

A) atm/s
B) atm/s
C) atm/s
D) atm/s
E) atm/s

Question 17

Two mechanisms are proposed: I. II. Which mechanism and which step as the rate determining step would best fit the data?

A)Mechanism I,with the first step the rate determining step.
B)Mechanism I,with the second step the rate determining step.
C)Mechanism II,with the first step rate determining.
D)Mechanism II,with the second step rate determining.
E)None of the above could be correct.

Question 18

The following initial rate data were found for the reaction
2MnO₄^- + 5H₂C₂O₄ + 6H⁺ $\to$ 2Mn²⁺ + 10CO₂ + 8H₂O


-Which of the following is the correct rate law?

A)Rate = k[MnO₄^-]²[H₂C₂O₄]⁵[H⁺]⁶
B)Rate = k[MnO₄^-]²[H₂C₂O₄][H⁺]
C)Rate = k[MnO₄^-][H₂C₂O₄][H⁺]
D)Rate = k[MnO₄^-]²[H₂C₂O₄]
E)Rate = k[MnO₄^-]²[H₂C₂O₄]²

Question 19

For the reaction ,at a particular instant in time,the rate of the reaction is 0.0223 M/s.What is the rate of change of A?

A)-0.0223 M/s
B)0.112 M/s
C)-0.112 M/s
D)-0.00446 M/s
E)0.00446 M/s

Question 20

A general reaction written as A + 2B $\to$ C + 2D is studied and yields the following data:


-What is the overall order of the reaction?

A)0
B)1
C)2
D)3
E)4

Question 21

The kinetics of the reaction were studied and the following results obtained,where the rate law is: For a run where [A]₀ = 1.0 $\times$ 10^-3 M and [B]₀ = 5.0 M,a plot of ln [A] versus t was found to give a straight line with slope = -5.0 $\times$ 10^-2 s^-1.
For a run where [A]₀ = 1.0 $\times$ 10^-3 M and [B]₀ = 10.0 M,a plot of ln [A] versus t was found to give a straight line with slope = -7.1 $\times$ 10^-2 s^-1.

-What is the value of n?

A)0
B)0.5
C)1
D)1.5
E)2

Question 22

The kinetics of the reaction were studied and the following results obtained,where the rate law is: For a run where [A]₀ = 1.0 $\times$ 10^-3 M and [B]₀ = 5.0 M,a plot of ln [A] versus t was found to give a straight line with slope = -5.0 $\times$ 10^-2 s^-1.
For a run where [A]₀ = 1.0 $\times$ 10^-3 M and [B]₀ = 10.0 M,a plot of ln [A] versus t was found to give a straight line with slope = -7.1 $\times$ 10^-2 s^-1.

-What is the value of m?

A)0
B)0.5
C)1
D)1.5
E)2

Question 23

What form will the pseudo-rate law have?

A)Rate = k'[A]^x
B)Rate = k'[B]^y
C)Rate = k'[A]^x[B]^y
D)Rate = kk'[A]^x
E)Rate = kk'[B]^y

Question 24

The following questions refer to the reaction between nitric oxide and hydrogen
2NO + H₂ $\to$ N₂O + H₂O


-What are the units for the rate constant for this reaction?

A)L/mol·s
B)L²/mol²·s
C)mol/L·s
D)s^-2
E)L^-2

Question 25

The reaction H₂SeO₃(aq)6I^-(aq)+ 4H⁺(aq) $\to$ 2I₃^-(aq)+ 3H₂O(l)+ Se(s)was studied at 0°C by the method of initial rates:



-The numerical value of the rate constant is

A)5.2 $\times$ 10⁵
B)2.1 $\times$ 10²
C)4.2
D)1.9 $\times$ 10^-6
E)none of these

Question 26

For the reaction ,the following data were collected:


-The order of this reaction in N₂O₅ is

A)0
B)1
C)2
D)3
E)none of these

Question 27

The initial rate of production of NO₂ for this reaction is approximately

A)7.4 $\times$ 10^-4 mol/L·min
B)3.2 $\times$ 10^-4 mol/L·min
C)1.24 $\times$ 10^-2 mol/L·min
D)1.6 $\times$ 10^-4 mol/L·min
E)none of these

Question 28

The rate expression for a particular reaction is rate = k[A][B]².If the initial concentration of B is increased from 0.1 M to 0.3 M,the initial rate will increase by which of the following factors?

A)2
B)6
C)12
D)3
E)9

Question 29

For a reaction: ,[A]₀ = 4.2 M,and the first two half-lives are 56 and 28 minutes,respectively.Calculate k (without units).

A)
B)
C)
D)
E)none of these

Question 30

For which order reaction is the half-life of the reaction proportional to 1/k (k is the rate constant)?

A)zero order
B)first order
C)second order
D)all of the above
E)none of the above

Question 31

The following questions refer to the reaction between nitric oxide and hydrogen
2NO + H₂ $\to$ N₂O + H₂O


-What is the order of this reaction?

A)3
B)2
C)1
D)0
E)cannot be determined from the data

Question 32

The half-life of this reaction is approximately

A)15 minutes
B)18 minutes
C)23 minutes
D)36 minutes
E)45 minutes

Question 33

The kinetics of the reaction were studied and the following results obtained,where the rate law is: For a run where [A]₀ = 1.0 $\times$ 10^-3 M and [B]₀ = 5.0 M,a plot of ln [A] versus t was found to give a straight line with slope = -5.0 $\times$ 10^-2 s^-1.
For a run where [A]₀ = 1.0 $\times$ 10^-3 M and [B]₀ = 10.0 M,a plot of ln [A] versus t was found to give a straight line with slope = -7.1 $\times$ 10^-2 s^-1.

-Calculate the value of k (ignore units).

A)22
B)10
C)50
D)1.1
E)none of these

Question 34

For a reaction: ,[A]₀ = 6.0 M,and the first two half-lives are 56 and 28 minutes,respectively.Calculate [A] at t = 105.9 minutes.

A)5.7 M
B)12 M
C)0.68 M
D)0.33 M
E)none of these

Question 35

The concentration of O₂ at t = 10.minutes is

A)2.0 $\times$ 10^-4 mol/L
B)0.32 $\times$ 10^-2 mol/L
C)0.16 $\times$ 10^-2 mol/L
D)0.64 $\times$ 10^-2 mol/L
E)none of these

Question 36

The following data were obtained for the reaction 2A + B $\to$ C where rate = $\Delta$ [C]/ $\Delta$ t

What is the value of the rate constant?

A)2.13
B)0.213
C)0.426
D)1.70
E)none of these

Question 37

The reaction H₂SeO₃(aq)6I^-(aq)+ 4H⁺(aq) $\to$ 2I₃^-(aq)+ 3H₂O(l)+ Se(s)was studied at 0°C by the method of initial rates:



-The rate law is

A)Rate = k[H₂SeO₃][H⁺][I^-]
B)Rate = k[H₂SeO₃][H⁺]²[I^-]
C)Rate = k[H₂SeO₃][H⁺][I^-]²
D)Rate = k[H₂SeO₃]²[H⁺][I^-]
E)Rate = k[H₂SeO₃][H⁺]²[I^-]³

Question 38

The concentration N₂O₅ at 100 minutes will be approximately

A)0.03 $\times$ 10^-2 mol/L
B)0.06 $\times$ 10^-2 mol/L
C)0.10 $\times$ 10^-2 mol/L
D)0.01 $\times$ 10^-2 mol/L
E)none of these

Question 39

The following questions refer to the reaction between nitric oxide and hydrogen
2NO + H₂ $\to$ N₂O + H₂O


-What is the magnitude of the rate constant for this reaction?

A)0.66
B)4.2 $\times$ 10^-3
C)870
D)1.9
E)300

Question 40

The reaction 2A + 5B $\to$ products is second order in A and first order in B.What is the rate law for this reaction?

A)rate = k[A]²[B]⁵
B)rate = k[A]¹[B]²
C)rate = k[A]²[B]¹
D)rate = k[A]⁵[B]²
E)rate = k[A]^2/7[B]^5/7

Question 41

The reaction exhibits the rate law where k = 1.0 $\times$ 10^-5 M^-1 . s^-1 at 25°C.This reaction is run where the initial concentration of NOBr ([NOBr]₀)is 1.00 $\times$ 10^-1 M. The [NO] after 1.00 hour has passed is

A)3.6 $\times$ 10^-4 M
B)9.9 $\times$ 10^-3 M
C)9.7 $\times$ 10^-3 M
D)1.0 $\times$ 10^-3 M
E)none of these

Question 42

The reaction A $\to$ B + C is known to be zero order in A with a rate constant of 5.0 $\times$ 10^-2 mol/L·s at 25°C.An experiment was run at 25°C where [A]₀ = 1.0 $\times$ 10^-3 M.

-The integrated rate law is

A)[A] = kt
B)[A] - [A]₀ = kt
C)
D)
E)[A]₀ - [A] = kt

Question 43

At a particular temperature,N₂O₅ decomposes according to a first-order rate law with a half-life of 3.0 s.If the initial concentration of N₂O₅ is 1.0 $\times$ 10¹⁶ molecules/cm³,what will be the concentration in molecules/cm³ after 16.1 s?

A)2.4 $\times$ 10¹⁴
B)3.3 $\times$ 10¹
C)1.0 $\times$ 10¹⁶
D)1.4 $\times$ 10¹⁴
E)2.3 $\times$ 10^-1

Question 44

The reaction is known to be zero order in A with a rate constant of 5.0 $\times$ 10^-2 mol/L s at 25°C.An experiment was run at 25°C where [A]₀ = 2.0 $\times$ 10^-3 M.After 5.0 minutes,the rate is

A)5.0 $\times$ 10^-2 mol/L·s
B)2.5 $\times$ 10^-2 mol/L·s
C)1.3 $\times$ 10^-2 mol/L·s
D)2.0 $\times$ 10^-3 mol/L·s
E)none of these

Question 45

The reaction exhibits the rate law where k = 1.0 $\times$ 10^-5 M^-1 s^-1 at 25°C.This reaction is run where the initial concentration of NOBr ([NOBr]₀)is 0.11 M.What is one half-life for this experiment?

A) s
B)
C) s
D) s
E)none of these

Question 46

A chemical reaction that is first order in X is observed to have a rate constant of 1.7 $\times$ 10^-2s^-1.If the initial concentration of X is 1.0 M,what is the concentration of X after 190 s?

A)25 M
B)0.68 M
C)0.24 M
D)0.96 M
E)0.040 M

Question 47

The OH· radical disproportionates according to the elementary chemical reaction This reaction is second order in OH·.The rate constant for the reaction is 2.0 $\times$ 10^-12 cm³/molecules at room temperature.If the initial OH concentration is 1.3 $\times$ 10¹³ molecules/cm³,what is the first half-life for the reaction?

A)3.5 $\times$ 10¹¹ s
B)2.6 $\times$ 10¹ s
C)3.8 $\times$ 10^-2 s
D)7.7 $\times$ 10^-14 s
E)1.9 $\times$ 10^-2 s

Question 48

Determine the magnitude of the pseudo-rate constant (k')if the magnitude of X in the rate data is 0.00905.

A)4.3 $\times$ 10^-3
B)1.2 $\times$ 10^-2
C)0.86
D)0.31
E)1.81 $\times$ 10^-3

Question 49

For the reaction A $\to$ Products,successive half-lives are observed to be 10.0 min and 40.0 min.

-The reaction follows the integrated rate law

A)
B)
C)
D)
E)none of these

Question 50

At a given temperature,a first-order reaction has a rate constant of 3.4 $\times$ 10^-3 s^-1.The time required for the reaction to be 44% completed is

A)4.0 min
B)1.2 min
C)20 min
D)2.8 min
E)19 min

Question 51

For the reaction A $\to$ Products,successive half-lives are observed to be 10.0 min and 40.0 min.

-The reaction is first order in N₂O₅.For this reaction at 45^oC,the rate constant k = 1.0 $\times$ 10^-5 s^-1,where the rate law is defined as For a particular experiment ([N₂O₅]₀ = 1.0 $\times$ 10^-3 M),calculate [N₂O₅] after 3.5 $\times$ 10⁵ seconds.

A)3.5 M
B)1.0 $\times$ 10^-3 M
C)3.0 $\times$ 10^-5 M
D)0 M
E)10 M

Question 52

Consider the reaction 3A + B + C $\to$ D + E where the rate law is defined as .
An experiment is carried out where [B]₀ = [C]₀ = 1.00 M and [A]₀ = 1.00 $\times$ 10^-4 M.

-The concentration of C after 10.0 minutes is

A)1.00 M
B)1.10 $\times$ 10^-5 M
C)0.330 M
D)0.100 M
E)none of these

Question 53

The reaction is known to be zero order in A with a rate constant of 5.0 $\times$ 10^-2 mol/L s at 25°C.An experiment was run at 25°C where [A]₀ = M.The half-life for the reaction is

A) s
B) s
C) s
D) s
E)none of these

Question 54

Consider the reaction 3A + B + C $\to$ D + E where the rate law is defined as .
An experiment is carried out where [B]₀ = [C]₀ = 1.00 M and [A]₀ = 1.00 $\times$ 10^-4 M.

-After 3.00 minutes,[A] = 3.26 $\times$ 10^-5 M.The value of k is

A)6.23 $\times$ 10^-3 L³/mol³·s
B)3.26 $\times$ 10^-5 L³/mol³·s
C)1.15 $\times$ 10² L³/mol³·s
D)1.00 $\times$ 10⁸ L³/mol³·s
E)none of these

Question 55

Consider the reaction 3A + B + C $\to$ D + E where the rate law is defined as .
An experiment is carried out where [B]₀ = [C]₀ = 1.00 M and [A]₀ = 1.00 $\times$ 10^-4 M.

-The concentration of A after 10.0 minutes is

A)1.06 $\times$ 10^-9 M
B)2.38 $\times$ 10^-6 M
C)9.80 $\times$ 10^-6 M
D)1.27 $\times$ 10^-5 M
E)none of these

Question 56

The reaction is second order in A.When [A]₀ = 0.100 M,the reaction is 20.0% complete in 35.9 minutes.Calculate the value of the rate constant (in L/min·mol).

A)6.96 $\times$ 10^-2
B)5.57 $\times$ 10^-4
C)1.57
D)1.11
E)none of these

Question 57

What is the concentration of B after 5 $\times$ 10^-3 sec?

A)5.0 $\times$ 10^-5 M
B)5.0 $\times$ 10^-4 M
C)7.5 $\times$ 10^-4 M
D)2.5 $\times$ 10^-4 M
E)none of these

Question 58

The reaction is second order in A.When [A]₀ = 0.100 M,the reaction is 20.0% complete in 43.2 minutes.Calculate the half-life for the reaction.

A)1.73 $\times$ 10² min
B)10.8 min
C)2.16 $\times$ 10⁴ min
D)7.68 min
E)none of these

Question 59

A first-order reaction is 40.0% complete at the end of 48.1 minutes.What is the value of the rate constant (in min^-1)?

A)1.90 $\times$ 10^-2
B)1.06 $\times$ 10^-2
C)94.2
D)52.5
E)none of these

Question 60

Consider the reaction 3A + B + C $\to$ D + E where the rate law is defined as .
An experiment is carried out where [B]₀ = [C]₀ = 1.00 M and [A]₀ = 1.00 $\times$ 10^-4 M.

-The half-life for this experiment is

A)1.11 $\times$ 10² s
B)87.0 s
C)6.03 $\times$ 10^-3 s
D)117 s
E)none of these

Question 61

Two isomers (A and B)of a given compound dimerize as follows:

Both processes are known to be second order in reactant,and k₁ is known to be 0.25 L/mol·s at 25°C,where

In a particular experiment,A and B were placed in separate containers at 25°,where [A]₀ = 1.0 $\times$ 10^-2 M and [B]₀ = 2.5 $\times$ 10^-2 M.It was found that [A] = 3[B] after the reactions progressed for 3.0 minutes.

-Calculate the concentration of A₂ after 3.0 minutes.

A)2.8 $\times$ 10^-22 M
B)6.9 $\times$ 10^-3 M
C)3.1 $\times$ 10^-3 M
D)1.6 $\times$ 10^-3 M
E)none of these

Question 62

The rate law for a reaction is found to be Rate = k[A]²[B].Which of the following mechanisms gives this rate law?
I.A + B E (fast)
E + B $\to$ C + D (slow)
II.A + B E (fast)
E + A $\to$ C + D (slow)
III.A + A $\to$ E (slow).
E + B $\to$ C + D (fast)

A)I
B)II
C)III
D)two of these
E)none of these

Question 63

A particular first-order reaction has a rate constant of 0.0107 s^-1.What is the half-life for this reaction?

A)1.00 s
B)64.6 s
C)93.2 s
D)0.0155 s
E)0.0107 s

Question 64

The experimental rate law for the decomposition of nitrous oxide (N₂O)to N₂ and O₂ is Rate = k[N₂O]².Two mechanisms are proposed:
I.N₂O $\to$ N₂ + O
N₂O + O $\to$ N₂ + O₂
II.2N₂O N₄O₂
N₄O₂ $\to$ 2N₂ + O₂
Which of the following could be a correct mechanism?

A)Mechanism I,with the first step as the rate-determining step.
B)Mechanism I,with the second step as the rate-determining step as long as the first step is a fast equilibrium step.
C)Mechanism II,with the second step as the rate-determining step if the first step is a fast equilibrium step.
D)None of the choices (A-C)could be correct.
E)At least two of the above choices (A-C)could be correct.

Question 65

The radioactive nuclide undergoes first-order decay with a half-life of 9.31 min.If a quantity of
Is produced,what fraction remains after 82.5 seconds?

A)0.113
B)0.00215
C)0.148
D)0.903
E)0.0973

Question 66

Determine the molecularity of the following elementary reaction: O₃ $\to$ O₂ + O.

A)unimolecular
B)bimolecular
C)termolecular
D)quadmolecular
E)molecularity cannot be determined

Question 67

Of what use is it to find a rate law for a reaction?

A)We can use the rate law to directly determine coefficients in the balanced equation.
B)From the rate law we can evaluate potential reaction mechanisms.
C)The rate law gives us a good indication of the thermodynamic stability of the products.
D)The rate law can lead us to determine the equilibrium constant for the reaction.
E)None of these.

Question 68

The reaction A $\to$ products is first order.If the initial concentration of A is 0.528 M and,after 16.3 seconds have elapsed,the concentration of A has fallen to 0.0122 M,what is the rate constant of the reaction?

A)0.231 s^-1
B)0.0425 s^-1
C)0.0316 s^-1
D)4.91 s^-1
E)0.0613 s^-1

Question 69

The reaction A $\to$ products is second order.If the initial concentration of A is 0.436 M and,after 52.8 seconds have elapsed,the concentration of A has fallen to 0.0476 M,what is the rate constant of the reaction?

A)0.0419 M^-1 s^-1
B)0.354 M^-1 s^-1
C)0.0131 M^-1 s^-1
D)0.00736 M^-1 s^-1
E)0.0189 M^-1 s^-1

Question 70

The decomposition of N₂O₅(g)to NO₂(g)and O₂(g)obeys first-order kinetics.Assuming the form of the rate law is:
Where k = 3.4 $\times$ 10^-5 s^-1 at 25°C,what is the initial rate of reaction at 25°C where [N₂O₅]₀ = 8.2 $\times$ 10^-2 M?

A) mol/L·s
B) mol/L·s
C) mol/L·s
D) mol/L·s
E)none of these

Question 71

If the reaction 2HI $\to$ H₂ + I₂ is second order,which of the following will yield a linear plot?

A)log [HI] vs time
B)1/[HI] vs time
C)[HI] vs time
D)ln [HI] vs time
E)None of these.

Question 72

The elementary chemical reaction O + ClO $\to$ Cl + O₂ is made pseudo-first order in oxygen atoms by using a large excess of ClO radicals.The rate constant for the reaction is 2.7 cm³/molecule.s.If the initial concentration of ClO is 1.0 $\times$ 10¹¹ molecules/cm³,how long will it take for the oxygen atoms to decrease to 10.% of their initial concentration?

A)1.2 s
B)0.039 s
C)0.26 s
D)0.85 s
E)2.6 s

Question 73

Two isomers (A and B)of a given compound dimerize as follows:

Both processes are known to be second order in reactant,and k₁ is known to be 0.25 L/mol·s at 25°C,where

In a particular experiment,A and B were placed in separate containers at 25°,where [A]₀ = 1.0 $\times$ 10^-2 M and [B]₀ = 2.5 $\times$ 10^-2 M.It was found that [A] = 3[B] after the reactions progressed for 3.0 minutes.

-Calculate the value of where

A)2.2 L/mol·s
B)0.75 L/mol·s
C)1.9 L/mol·s
D)0.21 L/mol·s
E)none of these

Question 74

Consider the reaction 2O₃(g) $\to$ 3O₂(g).The following mechanism is proposed: O₃ O₂ + O
O₃ + O $\to$ 2O₂
If we assume the second step of the mechanism is the rate determining step and the first step is a fast equilibrium step,which of the following rate laws is predicted by this mechanism?

A)rate = k[O₃]
B)rate = k[O₃]²[O₂]
C)rate = k[O₃]²[O₂]^-1
D)rate = k[O₃]²
E)none of these

Question 75

The decomposition of ozone may occur through the two-step mechanism shown: The oxygen atom is considered to be a(n)

A)reactant
B)product
C)catalyst
D)reaction intermediate
E)activated complex

Question 76

The reaction obeys the rate law: at 500.K. If the initial concentration of NO₂ is 1.00 M,how long will it take for the [NO₂] to decrease to 35.8% of its initial value?

A)45.9 s
B)73 s
C)128 s
D) s
E)cannot be determined from this data

Question 77

The decomposition of N₂O₅(g)to NO₂(g)and O₂(g)obeys first-order kinetics.Assuming the form of the rate law is:
Where k = 5.4 $\times$ 10^-5 s^-1 at 25°C,what is the half-life for the reaction described?

A) s
B) s
C) s
D) s
E)none of these

Question 78

In 6 M HCl,the complex ion Ru(NH₃)₆³⁺ decomposes to a variety of products.The reaction is first order in Ru(NH₃)₆³⁺ and has a half-life of 14 hours at 25°C.Under these conditions,how long will it take for the [Ru(NH₃)₆³⁺] to decrease to 23.5% of its initial value?

A)5.4 hours
B)9.7 hours
C)3.3 hours
D)14 hours
E)29 hours

Question 79

The reaction 3NO $\to$ N₂O + NO₂ is found to obey the rate law,Rate = k[NO]².If the first half-life of the reaction is found to be 2.0 s,what is the length of the fourth half-life?

A)2.0 s
B)4.0 s
C)8.0 s
D)12.0 s
E)16.0 s

Question 80

Consider a reaction of the type aA $\to$ Products in which the rate law is found to be rate = k[A]³ (yes,a termolecular reaction is improbable but possible).If the first half-life of the reaction is found to be 40 seconds,what is the time for the second half-life?

A)10 seconds
B)20 seconds
C)80 seconds
D)160 seconds
E)320 seconds