Question 1

The reaction
2H2(g)+ 2NO(g)→ 2H2O(g)+ N2(g)
Is first-order in H2 and second-order in NO at a particular temperature.What is the rate law?

Accepted Answer

A) Rate = k[H2]2[NO]2 
B) Rate = k[H2][NO]2 
C) Rate = k[H2][NO] 
D) Rate = k[H2O]2[N2] 
E) Rate = k[H2]2[NO] 
A) Rate = k[H2]2[NO]2 
B) Rate = k[H2][NO]2 
C) Rate = k[H2][NO] 
D) Rate = k[H2O]2[N2] 
E) Rate = k[H2]2[NO]

Question 2

For a certain reaction of the general form aA → products,a plot of the experimental data as [A] versus time is linear.What is the reaction order with respect to reactant A?

Accepted Answer

A) zero 
B) first 
C) second 
D) fourth 
E) third 
A) zero 
B) first 
C) second 
D) fourth 
E) third

Question 3

A reaction that is second-order in one reactant has a rate constant of 3.8 × 10-2 L/(mol ∙ s).If the initial concentration of the reactant is 0.280 mol/L,how long will it take for the concentration to become 0.140 mol/L?

Accepted Answer

A) 180 s 
B) 47 s 
C) 930 s 
D) 18 s 
E) 93 s 
A) 180 s 
B) 47 s 
C) 930 s 
D) 18 s 
E) 93 s

Question 4

The nuclide 188W decays by a first-order process with a rate constant of 1.0 × 10-2 d-1.How long will it take for 88% of the initial amount of 188W to be consumed?

Accepted Answer

A) 6 d 
B) 240 d 
C) 12 d 
D) 210 d 
E) 92 d 
A) 6 d 
B) 240 d 
C) 12 d 
D) 210 d 
E) 92 d

Question 5

For the hypothetical first-order reaction A → products,k = 0.0822 s-1.If the initial concentration of A is 0.372 M,how long would it take for A to be 28.2% consumed?

Accepted Answer

A) 8.43 s 
B) 4.03 s 
C) 12 s 
D) 32.7 s 
E) 15.3 s 
A) 8.43 s 
B) 4.03 s 
C) 12 s 
D) 32.7 s 
E) 15.3 s

Question 6

At 500oC,cyclopropane (C3H6)reacts to form its isomer,propene (C3H6).The reaction is first-order,and the rate constant is 6.7 × 10-4 s-1.If the initial concentration of cyclopropane is 0.500 M and the initial concentration of propene is 0,determine the time required for the concentration of propene to reach 0.100 M.

Accepted Answer

A) 3.4 × 103 s 
B) 3.3 × 102 s 
C) 1.2 × 104 s 
D) 7.5 × 102 s 
E) 2.4 × 103 s 
A) 3.4 × 103 s 
B) 3.3 × 102 s 
C) 1.2 × 104 s 
D) 7.5 × 102 s 
E) 2.4 × 103 s

Question 7

The reaction between selenous acid and the iodide ion in acid solution is
H2SeO3(aq)+ 6I-(aq)+ 4H+(aq)→ Se(s)+ 2I3-(aq)+ 3H2O(l)
The data in the following table were measured at 0°C.
Experiment
[H2SeO3]0 (M)
[H+]0 (M)
[I-]0 (M)
Initial Rate [mol/(L ∙ s)]
1
1)00 × 10-4
2)00 × 10-2
3)00 × 10-2
5)30 × 10-7
2
2)00 × 10-4
2)00 × 10-2
3)00 × 10-2
1)06 × 10-6
3
3)00 × 10-4
4)00 × 10-2
3)00 × 10-2
6)36 × 10-6
4
3)00 × 10-4
8)00 × 10-2
3)00 × 10-2
2)54 × 10-5
5
3)00 × 10-4
8)00 × 10-2
6)00 × 10-2
2)04 × 10-4
6
2)00 × 10-4
2)00 × 10-2
6)00 × 10-2
8)48 × 10-6
Tripling the initial concentration of H2SeO3 while holding the initial concentrations of H+ and I- constant increases the rate of the reaction by a factor of

Accepted Answer

A) 8. 
B) 4. 
C) 3. 
D) 2. 
E) 1. 
A) 8. 
B) 4. 
C) 3. 
D) 2. 
E) 1.

Question 8

For the elementary reaction A + B → C + D,what is the predicted rate law?

Accepted Answer

A) Rate = k[A]2 
B) Rate = k[A][B] 
C) Rate = k   
D) Rate = k[B]2 
E) Rate = k[A]/[C] 
A) Rate = k[A]2 
B) Rate = k[A][B] 
C) Rate = k   
D) Rate = k[B]2 
E) Rate = k[A]/[C]

Question 9

For the first-order reaction
1/2 N2O4(g)→ NO2(g); ΔH = 28.6 kJ
The activation energy is 53.7 kJ/mol.What is the activation energy for the reverse reaction?

Accepted Answer

A) 15.2 kJ/mol 
B) 82.3 kJ/mol 
C) -53.7 kJ/mol 
D) 25.1 kJ/mol 
E) 53.7 kJ/mol 
A) 15.2 kJ/mol 
B) 82.3 kJ/mol 
C) -53.7 kJ/mol 
D) 25.1 kJ/mol 
E) 53.7 kJ/mol

Question 10

A chemical reaction that is first-order in X is observed to have a rate constant of 2.00 × 10-2 s-1.If the initial concentration of X is 1.0 M,what is the concentration of X after 196 s?

Accepted Answer

A) 0.20 M 
B) 0.020 M 
C) 50 M 
D) 0.61 M 
E) 0.98 M 
A) 0.20 M 
B) 0.020 M 
C) 50 M 
D) 0.61 M 
E) 0.98 M

Question 11

For the reaction A + B + C → products,the following initial-rate data were obtained.
[A]0 (mol/L)
[B]0 (mol/L)
[C]0 (mol/L)
Initial Rate (mol/(L ∙ s))
0)40
0)40
0)20
0)0160
0)20
0)40
0)40
0)0080
0)60
0)10
0)20
0)0015
0)20
0)10
0)20
0)0005
0)20
0)20
0)40
0)0020
What are the reaction orders with respect to A,B,and C,respectively?

Accepted Answer

A) 0,1,1 
B) 1,2,1 
C) 1,1,1 
D) 1,2,0 
E) 0,2,1 
A) 0,1,1 
B) 1,2,1 
C) 1,1,1 
D) 1,2,0 
E) 0,2,1

Question 12

For the hypothetical reaction A + 2B → 2C + D,the initial rate of disappearance of A is 2.0 × 10-2 mol/(L ∙ s).What is the initial rate of disappearance of B?

Accepted Answer

A) 8.0 × 10-2 mol/(L ∙ s) 
B) 4 × 10-2 mol/(L ∙ s) 
C) 1.4 × 10-1 mol/(L ∙ s) 
D) 4.0 × 10-4 mol/(L ∙ s) 
E) 1.4 × 10-2 mol/(L ∙ s) 
A) 8.0 × 10-2 mol/(L ∙ s) 
B) 4 × 10-2 mol/(L ∙ s) 
C) 1.4 × 10-1 mol/(L ∙ s) 
D) 4.0 × 10-4 mol/(L ∙ s) 
E) 1.4 × 10-2 mol/(L ∙ s)

Question 13

Nitrosyl chloride is produced from the reaction of nitrogen monoxide and chlorine:
2NO(g)+ Cl2(g)→ 2NOCl(g)
The following initial rates at a given temperature were obtained for the concentrations listed below.
Experiment
Initial Rate (mol·L-1·h-1)
[NO]0 (mol·L-1)
[Cl2]0 (mol·L-1)
1
2)21
0)25
0)25
2
19)89
0)75
0)25
3
6)63
0)25
0)75
From the data,what is the experimental rate law?

Accepted Answer

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

Question 14

The reaction between selenous acid and the iodide ion in acid solution is
H2SeO3(aq)+ 6I-(aq)+ 4H+(aq)→ Se(s)+ 2I3-(aq)+ 3H2O(l)
The data in the following table were measured at 0°C.
Experiment
[H2SeO3]0 (M)
[H+]0 (M)
[I-]0 (M)
Initial Rate [mol/(L ∙ s)]
1
1)00 × 10-4
2)00 × 10-2
3)00 × 10-2
5)30 × 10-7
2
2)00 × 10-4
2)00 × 10-2
3)00 × 10-2
1)06 × 10-6
3
3)00 × 10-4
4)00 × 10-2
3)00 × 10-2
6)36 × 10-6
4
3)00 × 10-4
8)00 × 10-2
3)00 × 10-2
2)54 × 10-5
5
3)00 × 10-4
8)00 × 10-2
6)00 × 10-2
2)04 × 10-4
6
2)00 × 10-4
2)00 × 10-2
6)00 × 10-2
8)48 × 10-6
The overall order of this reaction is

Accepted Answer

A) 4. 
B) 6. 
C) 2. 
D) 8. 
E) 3. 
A) 4. 
B) 6. 
C) 2. 
D) 8. 
E) 3.

Question 15

Which of the following statements is incorrect?

Accepted Answer

A) The slow step in a mechanism generally involves a three-body collision. 
B) After the addition of a catalyst,the collision rate between molecules is still the same. 
C) Most collisions between reactant molecules do not lead to a product. 
D) Chemical reactions involve collisions between the participating molecules. 
E) A three-body collision is less likely than a two-body collision. 
A) The slow step in a mechanism generally involves a three-body collision. 
B) After the addition of a catalyst,the collision rate between molecules is still the same. 
C) Most collisions between reactant molecules do not lead to a product. 
D) Chemical reactions involve collisions between the participating molecules. 
E) A three-body collision is less likely than a two-body collision.

Question 16

A suggested mechanism for the decomposition of ozone is
O3  
O2 + O fast equilibrium
O + O3  
2O2  slow step
When the concentration of ozone is doubled and the concentration of oxygen is doubled,the instantaneous rate

Accepted Answer

A) increases by a factor of 8. 
B) remains the same. 
C) increases by a factor of 4. 
D) decreases. 
E) increases by a factor of 2. 
A) increases by a factor of 8. 
B) remains the same. 
C) increases by a factor of 4. 
D) decreases. 
E) increases by a factor of 2.

Question 17

If a reaction is zero-order in a reactant,when the concentration of the reactant is decreased by a factor of 2,the reaction rate will

Accepted Answer

A) quadruple. 
B) decrease by a factor of 1/2. 
C) remain constant. 
D) decrease by a factor of 1/4. 
E) double. 
A) quadruple. 
B) decrease by a factor of 1/2. 
C) remain constant. 
D) decrease by a factor of 1/4. 
E) double.

Question 18

Which of the following statements is incorrect?

Accepted Answer

A) The rates of most chemical reactions change with time. 
B) The rate constant for a reaction can be changed by changing the temperature. 
C) The rate constant is dependent on the reactant concentrations. 
D) In a series of stepwise reactions,the rate-determining step is the slowest one. 
E) The rate of a catalyzed reaction is dependent on the concentration of the catalyst. 
A) The rates of most chemical reactions change with time. 
B) The rate constant for a reaction can be changed by changing the temperature. 
C) The rate constant is dependent on the reactant concentrations. 
D) In a series of stepwise reactions,the rate-determining step is the slowest one. 
E) The rate of a catalyzed reaction is dependent on the concentration of the catalyst.

Question 19

The catalyzed pathway in a reaction mechanism has a __________ activation energy and thus causes a __________ reaction rate.

Accepted Answer

A) higher,lower 
B) higher,higher 
C) higher,steady 
D) lower,higher 
E) lower,steady 
A) higher,lower 
B) higher,higher 
C) higher,steady 
D) lower,higher 
E) lower,steady

Question 20

The hypochlorite ion oxidizes the iodide ion in aqueous solution as represented by the following equation:
OCl-(aq)+ I-(aq)→ OI-(aq)+ Cl-(aq)
The rate law for this reaction is Rate = k  
)The overall reaction order and the order with respect to OH- are

Accepted Answer

A) 2 and -1. 
B) 0 and -1. 
C) 0 and 1. 
D) 2 and 1. 
E) 1 and -1. 
A) 2 and -1. 
B) 0 and -1. 
C) 0 and 1. 
D) 2 and 1. 
E) 1 and -1.

The reaction 2H₂(g)+ 2NO(g)→ 2H₂O(g)+ N₂(g) Is first-order in H₂ and second-order in NO at a particular temperature.What is the rate law?

For a certain reaction of the general form aA → products,a plot of the experimental data as [A] versus time is linear.What is the reaction order with respect to reactant A?

A reaction that is second-order in one reactant has a rate constant of 3.8 × 10^-2 L/(mol ∙ s).If the initial concentration of the reactant is 0.280 mol/L,how long will it take for the concentration to become 0.140 mol/L?

The nuclide ¹⁸⁸W decays by a first-order process with a rate constant of 1.0 × 10^-2 d^-1.How long will it take for 88% of the initial amount of ¹⁸⁸W to be consumed?

For the hypothetical first-order reaction A → products,k = 0.0822 s^-1.If the initial concentration of A is 0.372 M,how long would it take for A to be 28.2% consumed?

For the elementary reaction A + B → C + D,what is the predicted rate law?

For the first-order reaction 1/2 N₂O₄(g)→ NO₂(g); ΔH = 28.6 kJ The activation energy is 53.7 kJ/mol.What is the activation energy for the reverse reaction?

A chemical reaction that is first-order in X is observed to have a rate constant of 2.00 × 10^-2 s^-1.If the initial concentration of X is 1.0 M,what is the concentration of X after 196 s?

For the hypothetical reaction A + 2B → 2C + D,the initial rate of disappearance of A is 2.0 × 10^-2 mol/(L ∙ s).What is the initial rate of disappearance of B?

Which of the following statements is incorrect?

A suggested mechanism for the decomposition of ozone is O₃ O₂ + O fast equilibrium O + O₃ 2O₂ slow step When the concentration of ozone is doubled and the concentration of oxygen is doubled,the instantaneous rate

If a reaction is zero-order in a reactant,when the concentration of the reactant is decreased by a factor of 2,the reaction rate will

Which of the following statements is incorrect?

The catalyzed pathway in a reaction mechanism has a activation energy and thus causes a reaction rate.

The hypochlorite ion oxidizes the iodide ion in aqueous solution as represented by the following equation: OCl^-(aq)+ I^-(aq)→ OI^-(aq)+ Cl^-(aq) The rate law for this reaction is Rate = k )The overall reaction order and the order with respect to OH^- are

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Exam 13: Rates of Reaction

The reaction 2H2(g)+ 2NO(g)→ 2H2O(g)+ N2(g) Is first-order in H2 and second-order in NO at a particular temperature.What is the rate law?

For a certain reaction of the general form aA → products,a plot of the experimental data as [A] versus time is linear.What is the reaction order with respect to reactant A?

A reaction that is second-order in one reactant has a rate constant of 3.8 × 10-2 L/(mol ∙ s).If the initial concentration of the reactant is 0.280 mol/L,how long will it take for the concentration to become 0.140 mol/L?

The nuclide 188W decays by a first-order process with a rate constant of 1.0 × 10-2 d-1.How long will it take for 88% of the initial amount of 188W to be consumed?

For the hypothetical first-order reaction A → products,k = 0.0822 s-1.If the initial concentration of A is 0.372 M,how long would it take for A to be 28.2% consumed?

For the elementary reaction A + B → C + D,what is the predicted rate law?

For the first-order reaction 1/2 N2O4(g)→ NO2(g); ΔH = 28.6 kJ The activation energy is 53.7 kJ/mol.What is the activation energy for the reverse reaction?

A chemical reaction that is first-order in X is observed to have a rate constant of 2.00 × 10-2 s-1.If the initial concentration of X is 1.0 M,what is the concentration of X after 196 s?

For the hypothetical reaction A + 2B → 2C + D,the initial rate of disappearance of A is 2.0 × 10-2 mol/(L ∙ s).What is the initial rate of disappearance of B?

Which of the following statements is incorrect?

A suggested mechanism for the decomposition of ozone is O3 O2 + O fast equilibrium O + O3 2O2 slow step When the concentration of ozone is doubled and the concentration of oxygen is doubled,the instantaneous rate

If a reaction is zero-order in a reactant,when the concentration of the reactant is decreased by a factor of 2,the reaction rate will

Which of the following statements is incorrect?

The catalyzed pathway in a reaction mechanism has a __________ activation energy and thus causes a __________ reaction rate.

The hypochlorite ion oxidizes the iodide ion in aqueous solution as represented by the following equation: OCl-(aq)+ I-(aq)→ OI-(aq)+ Cl-(aq) The rate law for this reaction is Rate = k )The overall reaction order and the order with respect to OH- are

Chemistry and Measurement

Atoms, molecules, and Ions

Calculations With Chemical Formulas and Equations

Chemical Reactions

The Gaseous State

Thermochemistry

Quantum Theory of the Atom

Electron Configurations and Periodicity

Ionic and Covalent Bonding

Molecular Geometry and Chemical Bonding Theory

States of Matter; Liquids and Solids

Solutions

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria

Solubility and Complex-Ion Equilibria

Thermodynamics and Equilibrium

Electrochemistry

Nuclear Chemistry

Chemistry of the Main-Group Metals

The Transition Elements and Coordination Compounds

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The reaction 2H₂(g)+ 2NO(g)→ 2H₂O(g)+ N₂(g) Is first-order in H₂ and second-order in NO at a particular temperature.What is the rate law?

A reaction that is second-order in one reactant has a rate constant of 3.8 × 10^-2 L/(mol ∙ s).If the initial concentration of the reactant is 0.280 mol/L,how long will it take for the concentration to become 0.140 mol/L?

The nuclide ¹⁸⁸W decays by a first-order process with a rate constant of 1.0 × 10^-2 d^-1.How long will it take for 88% of the initial amount of ¹⁸⁸W to be consumed?

For the hypothetical first-order reaction A → products,k = 0.0822 s^-1.If the initial concentration of A is 0.372 M,how long would it take for A to be 28.2% consumed?

For the first-order reaction 1/2 N₂O₄(g)→ NO₂(g); ΔH = 28.6 kJ The activation energy is 53.7 kJ/mol.What is the activation energy for the reverse reaction?

A chemical reaction that is first-order in X is observed to have a rate constant of 2.00 × 10^-2 s^-1.If the initial concentration of X is 1.0 M,what is the concentration of X after 196 s?

For the hypothetical reaction A + 2B → 2C + D,the initial rate of disappearance of A is 2.0 × 10^-2 mol/(L ∙ s).What is the initial rate of disappearance of B?

A suggested mechanism for the decomposition of ozone is O₃ O₂ + O fast equilibrium O + O₃ 2O₂ slow step When the concentration of ozone is doubled and the concentration of oxygen is doubled,the instantaneous rate

The catalyzed pathway in a reaction mechanism has a activation energy and thus causes a reaction rate.

The hypochlorite ion oxidizes the iodide ion in aqueous solution as represented by the following equation: OCl^-(aq)+ I^-(aq)→ OI^-(aq)+ Cl^-(aq) The rate law for this reaction is Rate = k )The overall reaction order and the order with respect to OH^- are