Question 1

For the hypothetical reaction A + 3B → 2C,the rate should be expressed as

Accepted Answer

A)  rate = Δ[A]/Δt.
B)  rate = -Δ[C]/Δt.
C)  rate = -3(Δ[B]/Δt) .
D)  rate = (1/2) (Δ[C]/Δt) .
E)  rate = (1/3) (Δ[B]/Δt) .

Question 2

The following is an Arrhenius plot of a first-order reaction.The rate constant is measured in units of s-1. -1.   Based on this Arrhenius plot,what is the Arrhenius frequency factor (A) of the reaction? (R =8.314 J/K mol)  A) 5.0 s-1 B) 40 s-1 C) 50 s-1 D) 5.0 × 103 s-1 E) 2.4 × 1017 s-1" class="answers-bank-image d-inline" rel="preload" > Based on this Arrhenius plot,what is the Arrhenius frequency factor (A) of the reaction? (R =8.314 J/K mol)

Accepted Answer

A)  5.0 s-1
B)  40 s-1
C)  50 s-1
D)  5.0 × 103 s-1
E)  2.4 × 1017 s-1

Question 3

Cyclopropane is converted to propene in a first-order process.The rate constant is 5.4 × 10-2 h-1.If the initial concentration of cyclopropane is 0.150 M,what will its concentration be after 22.0 hours?

Accepted Answer

A)  0.046 M
B)  0.11 M
C)  0.13 M
D)  0.49 M
E)  0.054 M

Question 4

The following diagram represents the zeroth-order decomposition of A to form X according to the following balanced chemical equation: A → X.Each sphere represents 1.0 mmol of atoms,and the volume of the box is 1.0 L.  What is the half-life of the reaction?

Accepted Answer

A)  15 s
B)  30 s
C)  36 s
D)  45 s
E)  60 s

Question 5

What is the half-life for a zeroth-order reaction?

Accepted Answer

A)  t1/2 = k
B)  t1/2 = 1/k[A]o
C)  t1/2 = 0.693/k[A]o
D)  t1/2 = [A]o/2k
E)  t1/2 = 0.693/k

Question 6

The rate constant for the reaction 3A → 4B is 6.00 × 10-3 L • mol-1 • min-1.How long will it take the concentration of A to drop from 0.75 M to 0.25 M?

Accepted Answer

A)  2.2 × 10-3 min
B)  5.5 × 10-3 min
C)  180 min
D)  440 min
E)  5.0 × 102min

Question 7

What is the half-life for a first-order reaction?

Accepted Answer

A)   
B)   
C)   
D)   
E)

Question 8

What is the name given to the slowest step in the mechanism of a reaction?

Accepted Answer

A)  Catalytic step
B)  Mechanistic step
C)  Rate-determining step
D)  Step 1
E)  Rate step

Question 9

A reaction intermediate is a species corresponding to a local energy maximum on a reaction energy diagram.

Accepted Answer

A) True 
 B)False

Question 10

Sucrose decomposes to fructose and glucose in acid solution.When ln [sucrose] is plotted vs.time,a straight line with slope of -0.208 h-1 results.What is the rate law for the reaction?

Accepted Answer

A)  Rate = (0.208 h-1) [sucrose]2
B)  Rate = (0.208 h-1) [sucrose]
C)  Rate = (0.0433 h) [sucrose]2
D)  Rate = (0.0433 h) [sucrose]
E)  Rate = (0.208 mol L-1 • h-1) [sucrose]0

Question 11

At 25°C the rate constant for the first-order decomposition of a pesticide solution is 6.40 × 10-3 min-1.If the starting concentration of pesticide is 0.0314 M,what concentration will remain after 62.0 min at 25°C?

Accepted Answer

A)  1.14 × 10-1 M
B)  47.4 M
C)  1.25 ×10-2 M
D)  2.11 × 10-2 M
E)  2.68 × 10-2 M

Question 12

What is the rate expression for the production of X,which is a gas,at constant volume?

Accepted Answer

A)  rate = PgVΔ[X]/RΔt
B)  rate = -TΔ[X]/PgVΔt
C)  rate = -PgV(Δ[X]/TΔt) 
D)  rate = (1/RT) (ΔPX/Δt) 
E)  rate = (1/RΔPX) (VT/Δt)

Question 13

The rate law for the rearrangement of CH3NC to CH3CN at 800 K is rate = (1300 s-1) [CH3NC]. What is the half-life for this reaction?

Accepted Answer

A)  7.69 × 10-4 s
B)  5.3 × 10-4 s
C)  1.9 × 10-3 s
D)  520 s
E)  1920 s

Question 14

Nitric oxide gas (NO) reacts with chlorine gas according to the equation 2 (M)          A) rate = k[NO] B) rate = k[NO][Cl2]1/2 C) rate = k[NO][Cl2] D) rate = k[NO]2[Cl2] E) rate = k[NO]2[Cl2]2" class="answers-bank-image d-inline" rel="preload" > The following initial rates of reaction have been measured for the given reagent concentrations. Cl2 (M)  2 (M)          A) rate = k[NO] B) rate = k[NO][Cl2]1/2 C) rate = k[NO][Cl2] D) rate = k[NO]2[Cl2] E) rate = k[NO]2[Cl2]2" class="answers-bank-image d-inline" rel="preload" > 2 (M)          A) rate = k[NO] B) rate = k[NO][Cl2]1/2 C) rate = k[NO][Cl2] D) rate = k[NO]2[Cl2] E) rate = k[NO]2[Cl2]2" class="answers-bank-image d-inline" rel="preload" > 2 (M)          A) rate = k[NO] B) rate = k[NO][Cl2]1/2 C) rate = k[NO][Cl2] D) rate = k[NO]2[Cl2] E) rate = k[NO]2[Cl2]2" class="answers-bank-image d-inline" rel="preload" > 2 (M)          A) rate = k[NO] B) rate = k[NO][Cl2]1/2 C) rate = k[NO][Cl2] D) rate = k[NO]2[Cl2] E) rate = k[NO]2[Cl2]2" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  rate = k[NO]
B)  rate = k[NO][Cl2]1/2
C)  rate = k[NO][Cl2]
D)  rate = k[NO]2[Cl2]
E)  rate = k[NO]2[Cl2]2

Question 15

Consider reactions A,B,and C,which have the potential energy profiles shown.Assuming that the reactions have roughly the same frequency factors,which reaction is the slowest?

Accepted Answer

A)  Reaction A
B)  Reaction B
C)  Reaction C
D)  All of the reactions have the same rate.

Question 16

A(n)_______________ is the name given to a collision that does result in a reaction.

Accepted Answer

The answer of A(n)_______________ is the name given to a...

Question 17

Which of the following is the correct unit for a second-order rate constant?

Accepted Answer

A)  s-1
B)  M • s-1
C)  M • s
D)  M-1 • s-1
E)  M-2 • s-1

Question 18

It takes 42.0 min for the concentration of a reactant in a first-order reaction to drop from 0.45 M to 0.32 M at 25°C.How long will it take for the reaction to be 90% complete?

Accepted Answer

A)  13.0 min
B)  86.0 min
C)  137 min
D)  222 min
E)  284 min

Question 19

The reaction CH3NC(g) → CH3CN(g) is first order with respect to methyl isocyanide,CH3NC.If it takes 10.3 minutes for exactly one quarter of the initial amount of methyl isocyanide to react,what is the rate constant in units of min-1?

Accepted Answer

A)  -0.135 min-1
B)  0.0279 min-1
C)  0.089 min-1
D)  0.135 min-1
E)  35.8 min-1

Question 20

The reaction A + 2B → products has been found to have the rate law,rate = k[A][B]2.While holding the concentration of A constant,the concentration of B is increased to three times its initial value.By what factor does the rate of reaction increase?

Accepted Answer

A)  3
B)  6
C)  9
D)  27
E)  30

Exam 14: Chemical Kinetics

The rate constant for the reaction 3A → 4B is 6.00 × 10-3 L • mol-1 • min-1.How long will it take the concentration of A to drop from 0.75 M to 0.25 M?

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Which of the following is the correct unit for a second-order rate constant?

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The reaction CH3NC(g) → CH3CN(g) is first order with respect to methyl isocyanide,CH3NC.If it takes 10.3 minutes for exactly one quarter of the initial amount of methyl isocyanide to react,what is the rate constant in units of min-1?

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Sucrose decomposes to fructose and glucose in acid solution.When ln [sucrose] is plotted vs.time,a straight line with slope of -0.208 h-1 results.What is the rate law for the reaction?

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Cyclopropane is converted to propene in a first-order process.The rate constant is 5.4 × 10-2 h-1.If the initial concentration of cyclopropane is 0.150 M,what will its concentration be after 22.0 hours?

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What is the rate expression for the production of X,which is a gas,at constant volume?

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A(n)_______________ is the name given to a collision that does result in a reaction.

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At 25°C the rate constant for the first-order decomposition of a pesticide solution is 6.40 × 10-3 min-1.If the starting concentration of pesticide is 0.0314 M,what concentration will remain after 62.0 min at 25°C?

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Nitric oxide gas (NO) reacts with chlorine gas according to the equation The following initial rates of reaction have been measured for the given reagent concentrations. Cl2 (M)

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A reaction intermediate is a species corresponding to a local energy maximum on a reaction energy diagram.

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The following is an Arrhenius plot of a first-order reaction.The rate constant is measured in units of s-1. Based on this Arrhenius plot,what is the Arrhenius frequency factor (A) of the reaction? (R =8.314 J/K mol)

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The rate law for the rearrangement of CH3NC to CH3CN at 800 K is rate = (1300 s-1) [CH3NC]. What is the half-life for this reaction?

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Consider reactions A,B,and C,which have the potential energy profiles shown.Assuming that the reactions have roughly the same frequency factors,which reaction is the slowest?

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What is the half-life for a first-order reaction?

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It takes 42.0 min for the concentration of a reactant in a first-order reaction to drop from 0.45 M to 0.32 M at 25°C.How long will it take for the reaction to be 90% complete?

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The reaction A + 2B → products has been found to have the rate law,rate = k[A][B]2.While holding the concentration of A constant,the concentration of B is increased to three times its initial value.By what factor does the rate of reaction increase?

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The following diagram represents the zeroth-order decomposition of A to form X according to the following balanced chemical equation: A → X.Each sphere represents 1.0 mmol of atoms,and the volume of the box is 1.0 L. What is the half-life of the reaction?

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What is the half-life for a zeroth-order reaction?

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For the hypothetical reaction A + 3B → 2C,the rate should be expressed as

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What is the name given to the slowest step in the mechanism of a reaction?

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The rate constant for the reaction 3A → 4B is 6.00 × 10^-3 L • mol^-1 • min^-1.How long will it take the concentration of A to drop from 0.75 M to 0.25 M?

Correct Answer
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The reaction CH₃NC(g) → CH₃CN(g) is first order with respect to methyl isocyanide,CH₃NC.If it takes 10.3 minutes for exactly one quarter of the initial amount of methyl isocyanide to react,what is the rate constant in units of min^-1?

Correct Answer
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Sucrose decomposes to fructose and glucose in acid solution.When ln [sucrose] is plotted vs.time,a straight line with slope of -0.208 h^-1 results.What is the rate law for the reaction?

Correct Answer
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Cyclopropane is converted to propene in a first-order process.The rate constant is 5.4 × 10^-2h^-1.If the initial concentration of cyclopropane is 0.150 M,what will its concentration be after 22.0 hours?

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Correct Answer
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Correct Answer
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At 25°C the rate constant for the first-order decomposition of a pesticide solution is 6.40 × 10^-3 min-1.If the starting concentration of pesticide is 0.0314 M,what concentration will remain after 62.0 min at 25°C?

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Nitric oxide gas (NO) reacts with chlorine gas according to the equation The following initial rates of reaction have been measured for the given reagent concentrations. Cl₂ (M)

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The following is an Arrhenius plot of a first-order reaction.The rate constant is measured in units of s^-1. Based on this Arrhenius plot,what is the Arrhenius frequency factor (A) of the reaction? (R =8.314 J/K mol)

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The rate law for the rearrangement of CH₃NC to CH₃CN at 800 K is rate = (1300 s^-1) [CH₃NC]. What is the half-life for this reaction?

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The reaction A + 2B → products has been found to have the rate law,rate = k[A][B]².While holding the concentration of A constant,the concentration of B is increased to three times its initial value.By what factor does the rate of reaction increase?

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