Question 1

B is a catalyst in the following mechanism:

Accepted Answer

A) True 
 B)False

Question 2

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

Question 3

The half life for a first order reaction is 45 min.What is the rate constant in units of s-1?

Accepted Answer

A) 0.015 s-1 
B) 65 s-1 
C) 2.6 x 10-4 s-1 
D) 3.9 x 103 s-1 
E) 1.9 x 103 s-1 
A) 0.015 s-1 
B) 65 s-1 
C) 2.6 x 10-4 s-1 
D) 3.9 x 103 s-1 
E) 1.9 x 103 s-1

Question 4

Concerning the decomposition of A, A $\rarr$ products, which of the following methods could be used to determine the order of the reaction with respect to A? I.Plot [A] vs time, ln[A] vs time, and 1/[A] vs time and identify which plot yields a straight line
II.Vary the concentration of A and note by what factor the rate changes
III.Identify if successive half lives of A double, halve, or stay constant

Accepted Answer

A) I only 
B) II only 
C) III only 
D) I and III 
E) I, II, and III 
A) I only 
B) II only 
C) III only 
D) I and III 
E) I, II, and III

Question 5

The reaction A + 2B $\rarr$ 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 6

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 × 10-2 min 
B) 2.5 min 
C) 23 min 
D) 29 min 
E) 230 min 
A) 3.4 × 10-2 min 
B) 2.5 min 
C) 23 min 
D) 29 min 
E) 230 min

Question 7

The following initial rate data apply to the reaction below. F2(g)+ 2Cl2O(g) $\rarr$2FClO2(g)+ Cl2(g) 
 
 Which of the following is the rate law (rate equation)for this reaction?

Accepted Answer

A) rate = k[F2]2[Cl2O]4 
B) rate = k[F2]2[Cl2O] 
C) rate = k[F2][Cl2O] 
D) rate = k[F2][Cl2O]2 
E) rate = k[F2]2[Cl2O]2 
A) rate = k[F2]2[Cl2O]4 
B) rate = k[F2]2[Cl2O] 
C) rate = k[F2][Cl2O] 
D) rate = k[F2][Cl2O]2 
E) rate = k[F2]2[Cl2O]2

Question 8

Given that Ea for a certain biological reaction is 48 kJ/mol and that the rate constant is 2.5 × 10-2 s-1 at 15°C, what is the rate constant at 37°C?

Accepted Answer

A) 2.7 × 10-2 s-1 
B) 2.5 × 10-1 s-1 
C) 1.0 × 10-1 s-1 
D) 6.0 × 10-3 s-1 
E) 1.1 s-1 
A) 2.7 × 10-2 s-1 
B) 2.5 × 10-1 s-1 
C) 1.0 × 10-1 s-1 
D) 6.0 × 10-3 s-1 
E) 1.1 s-1

Question 9

Nitric oxide reacts with chlorine to form nitrosyl chloride, NOCl.Use the following data to determine the rate equation for the reaction. 
NO + S1U1P11S1S1P0/S1U1B12S1U1B0ClS1U1B12S1U1$\rarr$ NOCl

Accepted Answer

A) rate = k[NO] 
B) rate = k[NO][ClS1U1B12S1U1B0]S1U1P11/2S1S1P0 
C) rate = k[NO][ClS1U1B12S1U1B0] 
D) rate = k[NO]S1U1P12S1S1P0[ClS1U1B12S1U1B0] 
E) rate = k[NO]S1U1P12S1S1P0[ClS1U1B12S1U1B0]S1U1P12S1S1P0 
A) rate = k[NO] 
B) rate = k[NO][ClS1U1B12S1U1B0]S1U1P11/2S1S1P0 
C) rate = k[NO][ClS1U1B12S1U1B0] 
D) rate = k[NO]S1U1P12S1S1P0[ClS1U1B12S1U1B0] 
E) rate = k[NO]S1U1P12S1S1P0[ClS1U1B12S1U1B0]S1U1P12S1S1P0

Question 10

For the chemical reaction system described by the diagram below, which statement is true?   If the Ea for the forward reaction is 25 kJ/mol and the enthalpy of reaction is -95 kJ/mol, what is Ea for the reverse reaction?

Accepted Answer

A) 120 kJ/mol 
B) 70 kJ/mol 
C) 95 kJ/mol 
D) 25 kJ/mol 
E) -70 kJ/mol 
A) 120 kJ/mol 
B) 70 kJ/mol 
C) 95 kJ/mol 
D) 25 kJ/mol 
E) -70 kJ/mol

Question 11

A reaction is experimentally found to follow the rate law, Rate = k[A]2 where k = 0.355 M-1min-1.Starting with [A]o = 1.55 M, how many seconds will it take for [A]t = 0.150M

Accepted Answer

A) 6.58 s 
B) 395 s 
C) 6.02 s 
D) 17.0 s 
E) 1.02 x 103 s 
A) 6.58 s 
B) 395 s 
C) 6.02 s 
D) 17.0 s 
E) 1.02 x 103 s

Question 12

The isomerization of methyl isocyanide, CH3NC $\rarr$CH3CN, follows first-order kinetics.The half-lives were found to be 161 min at 199°C and 12.5 min at 230°C.Calculate the activation energy for this reaction.

Accepted Answer

A) 6.17 × 10-3 kJ/mol 
B) 31.4 kJ/mol 
C) 78.2 kJ/mol 
D) 124 kJ/mol 
E) 163 kJ/mol 
A) 6.17 × 10-3 kJ/mol 
B) 31.4 kJ/mol 
C) 78.2 kJ/mol 
D) 124 kJ/mol 
E) 163 kJ/mol

Question 13

For the following exothermic reaction, the rate law at 298 K is rate = k [H2][I2].
H2(g)+ I2(g)$\rarr$ 2HI(g)
Predict the effect of each of the following changes on the initial rate of the reaction:
a.Addition of hydrogen gas at constant temperature and volume
b.Increase in volume of the reaction vessel at constant temperature
c.Addition of a catalyst
d.Increase in temperature

Accepted Answer

a.The initial rate increases.

Question 14

For the reaction X2 + Y + Z $\rarr$ XY + XZ, it is found that the rate equation is rate = k [X2][Y].Why does the concentration of Z have no effect on the rate?

Accepted Answer

A) The concentration of Z is very small and the others are very large. 
B) Z must react in a step after the rate determining step. 
C) Z is an intermediate. 
D) The fraction of molecules of Z that have very high energies is zero. 
E) The activation energy for Z to react is very high. 
A) The concentration of Z is very small and the others are very large. 
B) Z must react in a step after the rate determining step. 
C) Z is an intermediate. 
D) The fraction of molecules of Z that have very high energies is zero. 
E) The activation energy for Z to react is very high.

Question 15

The following mechanism has been suggested for the reaction:

H2O2 + 2H+ + 2I - $\rarr$ I2 + 2H2O

Identify the rate law that is consistent with this mechanism

Accepted Answer

A) Rate = k[H2O2][I-] 
B) Rate = k[HOI][OH-] 
C) Rate = k[OH-][H+] 
D) Rate = k[HOI][H+][I-] 
E) Rate = k[H2O2][[I-]2[H+]2 
A) Rate = k[H2O2][I-] 
B) Rate = k[HOI][OH-] 
C) Rate = k[OH-][H+] 
D) Rate = k[HOI][H+][I-] 
E) Rate = k[H2O2][[I-]2[H+]2

Question 16

Which of the following statements is false?

Accepted Answer

A) A catalyst increases the rate of the forward reaction, but does not alter the reverse rate. 
B) A catalyst alters the mechanism of reaction. 
C) A catalyst alters the activation energy. 
D) A catalyst may be altered in the reaction, but is always regenerated. 
E) A catalyst increases the rate of reaction, but is not consumed. 
A) A catalyst increases the rate of the forward reaction, but does not alter the reverse rate. 
B) A catalyst alters the mechanism of reaction. 
C) A catalyst alters the activation energy. 
D) A catalyst may be altered in the reaction, but is always regenerated. 
E) A catalyst increases the rate of reaction, but is not consumed.

Question 17

Benzoyl chloride, C6H5COCl, reacts with water to form benzoic acid, C6H5COOH, and hydrochloric acid.This first-order reaction is 25% complete after 26 s.How much longer would one have to wait in order to obtain 99% conversion of benzoyl chloride to benzoic acid?

Accepted Answer

A) 393 s 
B) 419 s 
C) 183 s 
D) 293 s 
E) 209 s 
A) 393 s 
B) 419 s 
C) 183 s 
D) 293 s 
E) 209 s

Question 18

It is possible for the following overall reaction to consist of a one step mechanism:
2A + B + C $\rarr$ products

Accepted Answer

A) True 
 B)False

Question 19

The oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the net reaction H3AsO4 + 3I - + 2 H3O + $\rarr$ H3AsO3 + I3- + H2O.The experimental rate law for this reaction is
Rate = k [H3AsO4] [I-] [H3O+].
According to the rate law for the reaction, an increase in the concentration of hydronium ion has what effect on this reaction?

Accepted Answer

The rate of reaction

Question 20

At 30°C, by how much is a reaction's activation energy decreased by the addition of a catalyst if the catalyst triples the reaction rate?

Accepted Answer

A) 2.77 kJ/mol 
B) 274 J/mol 
C) 2.70 J/mol 
D) 119 J/mol 
E) 1.20 kJ/mol 
A) 2.77 kJ/mol 
B) 274 J/mol 
C) 2.70 J/mol 
D) 119 J/mol 
E) 1.20 kJ/mol

B is a catalyst in the following mechanism:

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?

The half life for a first order reaction is 45 min.What is the rate constant in units of s^-1?

The reaction A + 2B $\rarr$ 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 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?

Given that E_a for a certain biological reaction is 48 kJ/mol and that the rate constant is 2.5 × 10^-2 s^-1at 15°C, what is the rate constant at 37°C?

Nitric oxide reacts with chlorine to form nitrosyl chloride, NOCl.Use the following data to determine the rate equation for the reaction. NO + ¹/₂Cl_{2S1U1 $\rarr$ NOCl}

For the chemical reaction system described by the diagram below, which statement is true? If the E_a for the forward reaction is 25 kJ/mol and the enthalpy of reaction is -95 kJ/mol, what is E_a for the reverse reaction?

A reaction is experimentally found to follow the rate law, Rate = k[A]² where k = 0.355 M^-1min^-1.Starting with [A]_o = 1.55 M, how many seconds will it take for [A]_t = 0.150M

The isomerization of methyl isocyanide, CH₃NC $\rarr$ CH₃CN, follows first-order kinetics.The half-lives were found to be 161 min at 199°C and 12.5 min at 230°C.Calculate the activation energy for this reaction.

For the reaction X₂ + Y + Z $\rarr$ XY + XZ, it is found that the rate equation is rate = k [X₂][Y].Why does the concentration of Z have no effect on the rate?

Which of the following statements is false?

Benzoyl chloride, C₆H₅COCl, reacts with water to form benzoic acid, C₆H₅COOH, and hydrochloric acid.This first-order reaction is 25% complete after 26 s.How much longer would one have to wait in order to obtain 99% conversion of benzoyl chloride to benzoic acid?

It is possible for the following overall reaction to consist of a one step mechanism: 2A + B + C $\rarr$ products

At 30°C, by how much is a reaction's activation energy decreased by the addition of a catalyst if the catalyst triples the reaction rate?

Chemistry: the Study of Change

Atoms, Molecules, and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Entropy Free Energy and Equilibrium

Electrochemistry

Nuclear Chemistry

Chemistry in the Atmosphere

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metal Chemistry and Coordination Compounds

Organic Chemistry

Synthetic and Natural Organic Polymers

Filters

Exam 13: Chemical Kinetics

B is a catalyst in the following mechanism:

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?

The half life for a first order reaction is 45 min.What is the rate constant in units of s-1?

The reaction A + 2B →\rarr→ 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 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 following initial rate data apply to the reaction below. F2(g)+ 2Cl2O(g) →\rarr→ 2FClO2(g)+ Cl2(g) Which of the following is the rate law (rate equation)for this reaction?

Given that Ea for a certain biological reaction is 48 kJ/mol and that the rate constant is 2.5 × 10-2 s-1 at 15°C, what is the rate constant at 37°C?

Nitric oxide reacts with chlorine to form nitrosyl chloride, NOCl.Use the following data to determine the rate equation for the reaction. NO + 1/2Cl2S1U1 →\rarr→ NOCl

For the chemical reaction system described by the diagram below, which statement is true? If the Ea for the forward reaction is 25 kJ/mol and the enthalpy of reaction is -95 kJ/mol, what is Ea for the reverse reaction?

A reaction is experimentally found to follow the rate law, Rate = k[A]2 where k = 0.355 M-1min-1.Starting with [A]o = 1.55 M, how many seconds will it take for [A]t = 0.150M

The isomerization of methyl isocyanide, CH3NC →\rarr→ CH3CN, follows first-order kinetics.The half-lives were found to be 161 min at 199°C and 12.5 min at 230°C.Calculate the activation energy for this reaction.

For the reaction X2 + Y + Z →\rarr→ XY + XZ, it is found that the rate equation is rate = k [X2][Y].Why does the concentration of Z have no effect on the rate?

The following mechanism has been suggested for the reaction: H2O2 + 2H+ + 2I - →\rarr→ I2 + 2H2O Identify the rate law that is consistent with this mechanism

Which of the following statements is false?

Benzoyl chloride, C6H5COCl, reacts with water to form benzoic acid, C6H5COOH, and hydrochloric acid.This first-order reaction is 25% complete after 26 s.How much longer would one have to wait in order to obtain 99% conversion of benzoyl chloride to benzoic acid?

It is possible for the following overall reaction to consist of a one step mechanism: 2A + B + C →\rarr→ products

At 30°C, by how much is a reaction's activation energy decreased by the addition of a catalyst if the catalyst triples the reaction rate?

Chemistry: the Study of Change

Atoms, Molecules, and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Entropy Free Energy and Equilibrium

Electrochemistry

Nuclear Chemistry

Chemistry in the Atmosphere

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metal Chemistry and Coordination Compounds

Organic Chemistry

Synthetic and Natural Organic Polymers

Filters

The half life for a first order reaction is 45 min.What is the rate constant in units of s^-1?

The reaction A + 2B $\rarr$ 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.

Given that E_a for a certain biological reaction is 48 kJ/mol and that the rate constant is 2.5 × 10^-2 s^-1at 15°C, what is the rate constant at 37°C?

Nitric oxide reacts with chlorine to form nitrosyl chloride, NOCl.Use the following data to determine the rate equation for the reaction. NO + ¹/₂Cl_{2S1U1 $\rarr$ NOCl}

For the chemical reaction system described by the diagram below, which statement is true? If the E_a for the forward reaction is 25 kJ/mol and the enthalpy of reaction is -95 kJ/mol, what is E_a for the reverse reaction?

A reaction is experimentally found to follow the rate law, Rate = k[A]² where k = 0.355 M^-1min^-1.Starting with [A]_o = 1.55 M, how many seconds will it take for [A]_t = 0.150M

The isomerization of methyl isocyanide, CH₃NC $\rarr$ CH₃CN, follows first-order kinetics.The half-lives were found to be 161 min at 199°C and 12.5 min at 230°C.Calculate the activation energy for this reaction.

For the reaction X₂ + Y + Z $\rarr$ XY + XZ, it is found that the rate equation is rate = k [X₂][Y].Why does the concentration of Z have no effect on the rate?

Benzoyl chloride, C₆H₅COCl, reacts with water to form benzoic acid, C₆H₅COOH, and hydrochloric acid.This first-order reaction is 25% complete after 26 s.How much longer would one have to wait in order to obtain 99% conversion of benzoyl chloride to benzoic acid?

It is possible for the following overall reaction to consist of a one step mechanism: 2A + B + C $\rarr$ products