Question 1

A first-order reaction has a rate constant of 3.00 F1F1F1S1F1F1F10 10-3 s-1. The time required for the reaction to be 75.0% complete is

Accepted Answer

A) 95.8 s 
B) 462 s 
C) 231 s 
D) 201 s 
E) 41.7 s 
A) 95.8 s 
B) 462 s 
C) 231 s 
D) 201 s 
E) 41.7 s

Question 2

The activation energy for a certain reaction is 113 kJ/mol. By what factor (how many times)will the rate constant increase when the temperature is raised from 310 K to 325 K?

Accepted Answer

The answer of The activation energy for a certain reaction...

Question 3

In which of the forms listed below would 0.5 g aluminum react the fastest with gaseous chlorine at 25°C?

Accepted Answer

A) 0.5 g aluminum in one piece 
B) 0.5 g aluminum divided into 10 pieces 
C) 0.5 g aluminum divided into 100 pieces 
D) 0.5 g aluminum divided into 1,000 pieces 
E) All the choices will react at the same rate since the temperature is the same. 
A) 0.5 g aluminum in one piece 
B) 0.5 g aluminum divided into 10 pieces 
C) 0.5 g aluminum divided into 100 pieces 
D) 0.5 g aluminum divided into 1,000 pieces 
E) All the choices will react at the same rate since the temperature is the same.

Question 4

For the first-order reaction, A F1F1F1S1F1F1F10 products, if half of the initial concentration of A reacts in 20 min, then the remaining half will completely react in the next 20 min.

Accepted Answer

A) True 
 B)False

Question 5

The Arrhenius equation is k = Ae-Ea/RT. The slope of a plot of ln k vs.1/T is equal to

Accepted Answer

A) -k 
B) k 
C) Ea 
D) -Ea /R 
E) A 
A) -k 
B) k 
C) Ea 
D) -Ea /R 
E) A

Question 6

Peroxodisulfate ion can oxidize iodide ions to iodine according to the balanced equation S2O82- + 2I - F1F1F1S1F1F1F10 2SO42- + I2.
The reaction is catalyzed by certain chemical species. Identify the catalyst in the following mechanism:
Step 1: Fe3+ + 2I - F1F1F1S1F1F1F10 Fe2+ + I2
 step 2: S2O82-  + Fe2+ F1F1F1S1F1F1F10 2SO42-  + Fe3+

Accepted Answer

A) Fe3+ 
B) I - 
C) S2O82- 
D) Fe2+ 
E) SO42- 
A) Fe3+ 
B) I - 
C) S2O82- 
D) Fe2+ 
E) SO42-

Question 7

A city's water supply is contaminated with a toxin at a concentration of 0.63 mg/L.For the water to be safe for drinking, the concentration of this toxin must be below 1.5 x 10-3 mg/L.Fortunately, this toxin decomposes to a safe mixture of products by first-order kinetics with a rate constant of 0.27 day-1.How long will it take for the water to be safe to drink?

Accepted Answer

A) 2.2 days 
B) 2.6 days 
C) 20.days 
D) 22 days 
E) 27 days 
A) 2.2 days 
B) 2.6 days 
C) 20.days 
D) 22 days 
E) 27 days

Question 8

What is the rate law that corresponds to the data shown for the reaction 2A + B F1F1F1S1F1F1F10 C?

Accepted Answer

The answer of What is the rate law that corresponds...

Question 9

The graphs below all refer to the same reaction. What is the order of this reaction?

Accepted Answer

A) zeroth order 
B) first order 
C) second order 
D) unable to predict 
A) zeroth order 
B) first order 
C) second order 
D) unable to predict

Question 10

A certain first-order reaction A F1F1F1S1F1F1F10 B is 25% complete in 42 min at 25°C. What is the half-life of the reaction?

Accepted Answer

A) 21 min 
B) 42 min 
C) 84 min 
D) 20 min 
E) 101 min 
A) 21 min 
B) 42 min 
C) 84 min 
D) 20 min 
E) 101 min

Question 11

Chlorine dioxide reacts in basic water to form chlorite and chlorate according to the following chemical equation: 2ClO2(aq)+ 2OH-(aq)F1F1F1S1F1F1F10 ClO2-(aq)+ ClO3-(aq)+ H2O(l)
A kinetic study of this reaction under a certain set of conditions yielded the data below.   Which one of the following is the rate law for this reaction?

Accepted Answer

A) rate = k[ClO2][OH-] 
B) rate = k[ClO2]2[OH-] 
C) rate = k[ClO2][OH-]2 
D) rate = k[ClO2]2[OH-]2 
E) rate = k[ClO2]4[OH-] 
A) rate = k[ClO2][OH-] 
B) rate = k[ClO2]2[OH-] 
C) rate = k[ClO2][OH-]2 
D) rate = k[ClO2]2[OH-]2 
E) rate = k[ClO2]4[OH-]

Question 12

For the hypothetical reaction A + 3B $\rarr$ 2C, the rate of appearance of C given by ($\Delta$[C]/$\Delta$t)may also be expressed as

Accepted Answer

A) ($\Delta$[C]/$\Delta$t = $\Delta$[A]/$\Delta$t) 
B) ($\Delta$[C]/$\Delta$t = -(3/2)$\Delta$[B]/$\Delta$t) 
C) ($\Delta$[C]/$\Delta$t = -(2/3)$\Delta$[B]/$\Delta$t) 
D) ($\Delta$[C]/$\Delta$t = -(1/2)$\Delta$[A]/$\Delta$t) 
A) ($\Delta$[C]/$\Delta$t = $\Delta$[A]/$\Delta$t) 
B) ($\Delta$[C]/$\Delta$t = -(3/2)$\Delta$[B]/$\Delta$t) 
C) ($\Delta$[C]/$\Delta$t = -(2/3)$\Delta$[B]/$\Delta$t) 
D) ($\Delta$[C]/$\Delta$t = -(1/2)$\Delta$[A]/$\Delta$t)

Question 13

A certain reaction A F1F1F1S1F1F1F10 products is second order in A. If this reaction is 10.% complete after 20.s, how long would it take for the reaction to be 90.% complete?

Accepted Answer

A) 180 s 
B) 1600 s 
C) 440 s 
D) 18,000 s 
E) 540 s 
A) 180 s 
B) 1600 s 
C) 440 s 
D) 18,000 s 
E) 540 s

Question 14

The reaction A + 2B F1F1F1S1F1F1F10 products was found to have the rate law, rate = k[A] [B]2.Predict by what factor the rate of reaction will increase when the concentration of A is doubled and the concentration of B is also doubled.

Accepted Answer

A) 2 
B) 4 
C) 6 
D) 8 
E) 9 
A) 2 
B) 4 
C) 6 
D) 8 
E) 9

Question 15

The activation energy of a certain uncatalyzed reaction is 64 kJ/mol. In the presence of a catalyst, the Ea is 55 kJ/mol. How many times faster is the catalyzed than the uncatalyzed reaction at 400°C? Assume that the frequency factor remains the same.

Accepted Answer

A) 5.0 times 
B) 1.16 times 
C) 15 times 
D) 2.0 times 
E) 0.2 times 
A) 5.0 times 
B) 1.16 times 
C) 15 times 
D) 2.0 times 
E) 0.2 times

Question 16

The activation energy for the reaction CH3CO F1F1F1S1F1F1F10 CH3 + CO is 71 kJ/mol. How many times greater is the rate constant for this reaction at 170°C than at 150°C?

Accepted Answer

A) 0.40 
B) 1.1 
C) 2.5 
D) 4.0 
E) 5.0 
A) 0.40 
B) 1.1 
C) 2.5 
D) 4.0 
E) 5.0

Question 17

Solids cannot react with gases.

Accepted Answer

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

Question 18

Appropriate units for a first-order rate constant are

Accepted Answer

A) M/s 
B) 1/M·s 
C) 1/s 
D) 1/M2·s 
A) M/s 
B) 1/M·s 
C) 1/s 
D) 1/M2·s

Question 19

The isomerization of cyclopropane to form propene is a first-order reaction.   At 760 K, 15% of a sample of cyclopropane changes to propene in 6.8 min.What is the half-life of cyclopropane at 760 K?

Accepted Answer

A) 3.4 F1F1F1S1F1F1F10 10-2 min 
B) 2.5 min 
C) 23 min 
D) 29 min 
E) 230 min 
A) 3.4 F1F1F1S1F1F1F10 10-2 min 
B) 2.5 min 
C) 23 min 
D) 29 min 
E) 230 min

Question 20

The reaction 2NO2(g)F1F1F1S1F1F1F10 2NO(g)+ O2(g)is suspected to be second order in NO2. Which of the following kinetic plots would be the most useful to confirm whether or not the reaction is second order?

Accepted Answer

A) a plot of [NO2]-1 vs.t 
B) a plot of ln [NO2] vs.t 
C) a plot of [NO2] vs.t 
D) a plot of ln [NO2]-1 vs.t 
E) a plot of [NO2]2 vs.t 
A) a plot of [NO2]-1 vs.t 
B) a plot of ln [NO2] vs.t 
C) a plot of [NO2] vs.t 
D) a plot of ln [NO2]-1 vs.t 
E) a plot of [NO2]2 vs.t

Exam 13: Chemical Kinetics

A first-order reaction has a rate constant of 3.00  10-3 s-1. The time required for the reaction to be 75.0% complete is

The activation energy for a certain reaction is 113 kJ/mol. By what factor (how many times)will the rate constant increase when the temperature is raised from 310 K to 325 K?

In which of the forms listed below would 0.5 g aluminum react the fastest with gaseous chlorine at 25°C?

For the first-order reaction, A  products, if half of the initial concentration of A reacts in 20 min, then the remaining half will completely react in the next 20 min.

The Arrhenius equation is k = Ae-Ea/RT. The slope of a plot of ln k vs.1/T is equal to

Peroxodisulfate ion can oxidize iodide ions to iodine according to the balanced equation S2O82- + 2I -  2SO42- + I2. The reaction is catalyzed by certain chemical species. Identify the catalyst in the following mechanism: Step 1: Fe3+ + 2I -  Fe2+ + I2 step 2: S2O82- + Fe2+  2SO42- + Fe3+

What is the rate law that corresponds to the data shown for the reaction 2A + B  C?

The graphs below all refer to the same reaction. What is the order of this reaction?

A certain first-order reaction A  B is 25% complete in 42 min at 25°C. What is the half-life of the reaction?

For the hypothetical reaction A + 3B →\rarr→ 2C, the rate of appearance of C given by ( Δ\DeltaΔ [C]/ Δ\DeltaΔ t)may also be expressed as

A certain reaction A  products is second order in A. If this reaction is 10.% complete after 20.s, how long would it take for the reaction to be 90.% complete?

The reaction A + 2B  products was found to have the rate law, rate = k[A] [B]2.Predict by what factor the rate of reaction will increase when the concentration of A is doubled and the concentration of B is also doubled.

The activation energy of a certain uncatalyzed reaction is 64 kJ/mol. In the presence of a catalyst, the Ea is 55 kJ/mol. How many times faster is the catalyzed than the uncatalyzed reaction at 400°C? Assume that the frequency factor remains the same.

The activation energy for the reaction CH3CO  CH3 + CO is 71 kJ/mol. How many times greater is the rate constant for this reaction at 170°C than at 150°C?

Solids cannot react with gases.

Appropriate units for a first-order rate constant are

The isomerization of cyclopropane to form propene is a first-order reaction. At 760 K, 15% of a sample of cyclopropane changes to propene in 6.8 min.What is the half-life of cyclopropane at 760 K?

The reaction 2NO2(g) 2NO(g)+ O2(g)is suspected to be second order in NO2. Which of the following kinetic plots would be the most useful to confirm whether or not the reaction is second order?

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A first-order reaction has a rate constant of 3.00  10^-3s^-1. The time required for the reaction to be 75.0% complete is

The Arrhenius equation is k = Ae^-Ea/RT. The slope of a plot of ln k vs.1/T is equal to

For the hypothetical reaction A + 3B $\rarr$ 2C, the rate of appearance of C given by ( $\Delta$ [C]/ $\Delta$ t)may also be expressed as

The reaction A + 2B  products was found to have the rate law, rate = k[A] [B]².Predict by what factor the rate of reaction will increase when the concentration of A is doubled and the concentration of B is also doubled.

The activation energy of a certain uncatalyzed reaction is 64 kJ/mol. In the presence of a catalyst, the E_a is 55 kJ/mol. How many times faster is the catalyzed than the uncatalyzed reaction at 400°C? Assume that the frequency factor remains the same.

The activation energy for the reaction CH₃CO  CH₃ + CO is 71 kJ/mol. How many times greater is the rate constant for this reaction at 170°C than at 150°C?

The reaction 2NO₂(g) 2NO(g)+ O₂(g)is suspected to be second order in NO₂. Which of the following kinetic plots would be the most useful to confirm whether or not the reaction is second order?