Question 1

The Arrhenius equation,   expresses the dependence of the rate constant on the reaction temperature.The slope of a plot of ln(k)versus 1/T is equal to

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 2

For a certain reaction of the general form aA → products,the experimental data plotted as 1/[A] versus time is linear.The slope of this plot must equal

Accepted Answer

A) -1. 
B) the rate constant. 
C) one over the rate constant. 
D) the negative of the rate constant. 
E) 1. 
A) -1. 
B) the rate constant. 
C) one over the rate constant. 
D) the negative of the rate constant. 
E) 1.

Question 3

The rate law for the hydrolysis of thioacetamide (CH3CSNH2),
CH3CSNH2(aq)+ H2O(l)→ H2S(g)+ CH3CONH2(aq)
Is Rate = k[H+][CH3CSNH2].If,during the course of the reaction,some solid sodium hydroxide is added to the reaction mixture,then

Accepted Answer

A) the reaction rate decreases,but k remains the same. 
B) the reaction rate remains the same,but k decreases. 
C) the reaction rate increases,but k remains the same. 
D) there is no change in the reaction rate or the rate constant. 
E) the reaction rate remains the same,but k increases. 
A) the reaction rate decreases,but k remains the same. 
B) the reaction rate remains the same,but k decreases. 
C) the reaction rate increases,but k remains the same. 
D) there is no change in the reaction rate or the rate constant. 
E) the reaction rate remains the same,but k increases.

Question 4

The reaction CHCl3(g)+ Cl2(g)   CCl4(g)+ HCl(g)has been proposed to occur by the following mechanism.
Cl2  
2Cl fast equilibrium
CHCl3 + Cl  
HCl + CCl3 slow step
CCl3 + Cl  
CCl4 fast
What is the rate law predicted by this mechanism?

Accepted Answer

A) Rate = kexp[CHCl3][Cl2] 
B) Rate = k2[CHCl3][Cl] 
C) Rate = k1[Cl2] 
D) Rate = k3[CCl3][Cl] 
E) Rate = k2(k1/k-1)1/2[CHCl3][Cl2]1/2 
A) Rate = kexp[CHCl3][Cl2] 
B) Rate = k2[CHCl3][Cl] 
C) Rate = k1[Cl2] 
D) Rate = k3[CCl3][Cl] 
E) Rate = k2(k1/k-1)1/2[CHCl3][Cl2]1/2

Question 5

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  
)If time is measured in seconds and concentration is measured in moles per liter,what are the units for k?

Accepted Answer

A) mol2/(L2 ∙ s) 
B) L/(mol ∙ s) 
C) 1/s 
D) L2/(mol2 ∙ s) 
E) mol/(L ∙ s) 
A) mol2/(L2 ∙ s) 
B) L/(mol ∙ s) 
C) 1/s 
D) L2/(mol2 ∙ s) 
E) mol/(L ∙ s)

Question 6

The reaction A → products is first-order in A.If the concentration of A is cut in half,the half-life of the reaction will

Accepted Answer

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

Question 7

The rate law for the reaction between chlorine and nitric oxide,
2NO(g)+ Cl2(g)→ 2NOCl(g)
Is Rate = k[NO]2[Cl2].Which of the following changes will not alter the initial rate of the reaction?

Accepted Answer

A) increasing the concentration of NOCl 
B) decreasing the volume of the reaction system 
C) running the reaction in a solvent rather than in the gas phase 
D) increasing the volume of the reaction system 
E) increasing the concentration of chlorine gas 
A) increasing the concentration of NOCl 
B) decreasing the volume of the reaction system 
C) running the reaction in a solvent rather than in the gas phase 
D) increasing the volume of the reaction system 
E) increasing the concentration of chlorine gas

Question 8

What would happen if the kinetic energy of the reactants were not enough to provide the needed activation energy?

Accepted Answer

A) The rate of the reaction would tend to increase. 
B) The reactants would continue to exist in their present form. 
C) The activated complex would be converted into products. 
D) The products would be produced at a lower energy state. 
E) The products would form at an unstable energy state. 
A) The rate of the reaction would tend to increase. 
B) The reactants would continue to exist in their present form. 
C) The activated complex would be converted into products. 
D) The products would be produced at a lower energy state. 
E) The products would form at an unstable energy state.

Question 9

Which of the following statements is incorrect concerning a catalyst?

Accepted Answer

A) A catalyst decreases the activation energy of a reaction. 
B) A catalyst may appear in the rate law for a reaction. 
C) A catalyst alters the equilibrium distribution of reactants and products. 
D) There is no net consumption of a catalyst in a reaction. 
E) A catalyst provides an alternative reaction mechanism. 
A) A catalyst decreases the activation energy of a reaction. 
B) A catalyst may appear in the rate law for a reaction. 
C) A catalyst alters the equilibrium distribution of reactants and products. 
D) There is no net consumption of a catalyst in a reaction. 
E) A catalyst provides an alternative reaction mechanism.

Question 10

The following data were obtained in a kinetics study of the hypothetical reaction A + B + C → products.
[A]0 (M)
[B]0 (M)
[C]0 (M)
Initial Rate (10-3 M/s)
0)4
0)4
0)2
160
0)2
0)4
0)4
80
0)6
0)1
0)2
15
0)2
0)1
0)2
5
0)2
0)2
0)4
20
Using the initial-rate method,what is the order of the reaction with respect to C?

Accepted Answer

A) zero-order 
B) first-order 
C) third-order 
D) second-order 
E) impossible to tell from the data given 
A) zero-order 
B) first-order 
C) third-order 
D) second-order 
E) impossible to tell from the data given

Question 11

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 → C + D (slow)
II.A + B  
E (fast)
E + A → C + D (slow)
III.A + A → E (slow).
E + B → C + D (fast)

Accepted Answer

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

Question 12

For the formation of 1 mol of nitrosyl chloride at a given temperature,ΔH = -38 kJ.
NO(g)+ 1/2 Cl2(g)→ NOCl(g)
The activation energy for this reaction is 69 kJ/mol.What is the activation energy for the reverse reaction?

Accepted Answer

A) 69 kJ/mol 
B) 31 kJ/mol 
C) 107 kJ/mol 
D) -38 kJ/mol 
E) -107 kJ/mol 
A) 69 kJ/mol 
B) 31 kJ/mol 
C) 107 kJ/mol 
D) -38 kJ/mol 
E) -107 kJ/mol

Question 13

Which of the following corresponds to the correct equation for the half-life of a first-order reaction?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 14

For the following reaction producing 1 mol of oxygen gas at a particular temperature,ΔH = -200 kJ.
NO(g)+ O3(g)→ NO2(g)+ O2(g)
The activation energy is 11 kJ/mol.What is the activation energy for the reverse reaction?

Accepted Answer

A) 11 kJ/mol 
B) 200 kJ/mol 
C) 222 kJ/mol 
D) 188 kJ/mol 
E) 211 kJ/mol 
A) 11 kJ/mol 
B) 200 kJ/mol 
C) 222 kJ/mol 
D) 188 kJ/mol 
E) 211 kJ/mol

Question 15

A proposed mechanism for the decomposition of N2O5 is as follows:
N2O5  
NO2 + NO3
Slow step
NO2 + NO3  
NO2 + O2 + NO
Fast step
NO + N2O5  
3NO2
Fast step
What is the overall chemical equation predicted by this mechanism?

Accepted Answer

A) N2O5 + NO2 + NO3 → 4NO2 + O2 
B) N2O5 + NO → 3NO2 
C) 2N2O5 → 4NO2 + O2 
D) N2O5 → NO2 + NO3 
E) N2O5 → NO2 + O2 + NO 
A) N2O5 + NO2 + NO3 → 4NO2 + O2 
B) N2O5 + NO → 3NO2 
C) 2N2O5 → 4NO2 + O2 
D) N2O5 → NO2 + NO3 
E) N2O5 → NO2 + O2 + NO

Question 16

For the hypothetical reaction aA → products,the experimental data showed the following behavior (below).What is the reaction order with respect to reactant A?

Accepted Answer

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

Question 17

The rate constant for a first-order reaction is 2.4 × 10-4 L/(mol·s)at 600 K and 6.2 × 10-4 L/(mol · s)at 900 K.Calculate the activation energy.(R = 8.31 J/(mol · K))

Accepted Answer

A) ​2.55 × 104 J/mol 
B) 1.42 × 102 J/mol 
C) 1.42 × 104 J/mol 
D) ​1.04 × 103 J/mol 
E) ​0.88 × 104 J/mol 
A) ​2.55 × 104 J/mol 
B) 1.42 × 102 J/mol 
C) 1.42 × 104 J/mol 
D) ​1.04 × 103 J/mol 
E) ​0.88 × 104 J/mol

Question 18

Determine the molecularity of the following elementary reaction: O3 → O2 + O.

Accepted Answer

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

Question 19

The radioactive nuclide 63Ni decays by a first-order process via the emission of a beta particle.The 63Ni nuclide has a half-life of 100.years.How long will it take for 71% of 63Ni to decay?

Accepted Answer

A) 49.4 years 
B) 21.4 years 
C) 0.857 years 
D) 178 years 
E) 77.5 years 
A) 49.4 years 
B) 21.4 years 
C) 0.857 years 
D) 178 years 
E) 77.5 years

Question 20

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 H+ while holding the initial concentrations of H2SeO3 and I- constant increases the initial rate of the reaction by a factor of

Accepted Answer

A) 9. 
B) 16. 
C) 32. 
D) 2. 
E) 4. 
A) 9. 
B) 16. 
C) 32. 
D) 2. 
E) 4.

Exam 13: Rates of Reaction

The Arrhenius equation, expresses the dependence of the rate constant on the reaction temperature.The slope of a plot of ln(k)versus 1/T is equal to

For a certain reaction of the general form aA → products,the experimental data plotted as 1/[A] versus time is linear.The slope of this plot must equal

The rate law for the hydrolysis of thioacetamide (CH3CSNH2), CH3CSNH2(aq)+ H2O(l)→ H2S(g)+ CH3CONH2(aq) Is Rate = k[H+][CH3CSNH2].If,during the course of the reaction,some solid sodium hydroxide is added to the reaction mixture,then

The reaction CHCl3(g)+ Cl2(g) CCl4(g)+ HCl(g)has been proposed to occur by the following mechanism. Cl2 2Cl fast equilibrium CHCl3 + Cl HCl + CCl3 slow step CCl3 + Cl CCl4 fast What is the rate law predicted by this mechanism?

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 )If time is measured in seconds and concentration is measured in moles per liter,what are the units for k?

The reaction A → products is first-order in A.If the concentration of A is cut in half,the half-life of the reaction will

The rate law for the reaction between chlorine and nitric oxide, 2NO(g)+ Cl2(g)→ 2NOCl(g) Is Rate = k[NO]2[Cl2].Which of the following changes will not alter the initial rate of the reaction?

What would happen if the kinetic energy of the reactants were not enough to provide the needed activation energy?

Which of the following statements is incorrect concerning a catalyst?

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 → C + D (slow) II.A + B E (fast) E + A → C + D (slow) III.A + A → E (slow). E + B → C + D (fast)

For the formation of 1 mol of nitrosyl chloride at a given temperature,ΔH = -38 kJ. NO(g)+ 1/2 Cl2(g)→ NOCl(g) The activation energy for this reaction is 69 kJ/mol.What is the activation energy for the reverse reaction?

Which of the following corresponds to the correct equation for the half-life of a first-order reaction?

For the following reaction producing 1 mol of oxygen gas at a particular temperature,ΔH = -200 kJ. NO(g)+ O3(g)→ NO2(g)+ O2(g) The activation energy is 11 kJ/mol.What is the activation energy for the reverse reaction?

A proposed mechanism for the decomposition of N2O5 is as follows: N2O5 NO2 + NO3 Slow step NO2 + NO3 NO2 + O2 + NO Fast step NO + N2O5 3NO2 Fast step What is the overall chemical equation predicted by this mechanism?

For the hypothetical reaction aA → products,the experimental data showed the following behavior (below).What is the reaction order with respect to reactant A?

The rate constant for a first-order reaction is 2.4 × 10-4 L/(mol·s)at 600 K and 6.2 × 10-4 L/(mol · s)at 900 K.Calculate the activation energy.(R = 8.31 J/(mol · K))

Determine the molecularity of the following elementary reaction: O3 → O2 + O.

The radioactive nuclide 63Ni decays by a first-order process via the emission of a beta particle.The 63Ni nuclide has a half-life of 100.years.How long will it take for 71% of 63Ni to decay?

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The rate law for the hydrolysis of thioacetamide (CH₃CSNH₂), CH₃CSNH₂(aq)+ H₂O(l)→ H₂S(g)+ CH₃CONH₂(aq) Is Rate = k[H⁺][CH₃CSNH₂].If,during the course of the reaction,some solid sodium hydroxide is added to the reaction mixture,then

The reaction CHCl₃(g)+ Cl₂(g) CCl₄(g)+ HCl(g)has been proposed to occur by the following mechanism. Cl₂ 2Cl fast equilibrium CHCl₃ + Cl HCl + CCl₃ slow step CCl₃ + Cl CCl₄ fast What is the rate law predicted by this mechanism?

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 )If time is measured in seconds and concentration is measured in moles per liter,what are the units for k?

The rate law for the reaction between chlorine and nitric oxide, 2NO(g)+ Cl₂(g)→ 2NOCl(g) Is Rate = k[NO]²[Cl₂].Which of the following changes will not alter the initial rate of the reaction?

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 → C + D (slow) II.A + B E (fast) E + A → C + D (slow) III.A + A → E (slow). E + B → C + D (fast)

For the formation of 1 mol of nitrosyl chloride at a given temperature,ΔH = -38 kJ. NO(g)+ 1/2 Cl₂(g)→ NOCl(g) The activation energy for this reaction is 69 kJ/mol.What is the activation energy for the reverse reaction?

For the following reaction producing 1 mol of oxygen gas at a particular temperature,ΔH = -200 kJ. NO(g)+ O₃(g)→ NO₂(g)+ O₂(g) The activation energy is 11 kJ/mol.What is the activation energy for the reverse reaction?

A proposed mechanism for the decomposition of N₂O₅ is as follows: N₂O₅ NO₂ + NO₃ Slow step NO₂ + NO₃ NO₂ + O₂ + NO Fast step NO + N₂O₅ 3NO₂ Fast step What is the overall chemical equation predicted by this mechanism?

The rate constant for a first-order reaction is 2.4 × 10^-4L/(mol·s)at 600 K and 6.2 × 10^-4L/(mol · s)at 900 K.Calculate the activation energy.(R = 8.31 J/(mol · K))

Determine the molecularity of the following elementary reaction: O₃ → O₂ + O.

The radioactive nuclide ⁶³Ni decays by a first-order process via the emission of a beta particle.The ⁶³Ni nuclide has a half-life of 100.years.How long will it take for 71% of ⁶³Ni to decay?