Question 1

Heterogeneous catalysts have different phases from reactants.

Accepted Answer

A) True 
 B)False

Question 2

The reaction
2NO2 → 2NO + O2
Follows second- order kinetics. At 300°C, [NO2] drops from 0.0100- to 0.00650- M in 100 s. The rate constant for the reaction is _ M- 1s- 1.

Accepted Answer

A)  1.2 
B)  0.096 
C)  0.65 
D)  0.54 
E)  0.81 
A)  1.2 
B)  0.096 
C)  0.65 
D)  0.54 
E)  0.81

Question 3

At elevated temperatures, dinitrogen pentoxide decomposes to nitrogen dioxide and oxygen:
2N2O5(g) → 4NO2 (g) + O2 (g)
When the rate of formation of NO2 is 5.5 × 10- 4 M/s, the rate of decomposition of N2O5 is
M/s)

Accepted Answer

A)  10.1 × 10- 4 
B)  5.5 × 10- 4 
C)  2.8 × 10- 4 
D)  2.2 × 10- 3 
E)  1.4 × 10- 4 
A)  10.1 × 10- 4 
B)  5.5 × 10- 4 
C)  2.8 × 10- 4 
D)  2.2 × 10- 3 
E)  1.4 × 10- 4

Question 4

The average rate of disappearance of I- between 400 s and 800 s is M/s.

Accepted Answer

A)  1.4 × 10- 5  
B)  3.6 × 104  
C)  5.8 × 10- 5  
D)  2.6 × 10- 4  
E)  2.8 × 10- 5 
A)  1.4 × 10- 5  
B)  3.6 × 104  
C)  5.8 × 10- 5  
D)  2.6 × 10- 4  
E)  2.8 × 10- 5

Question 5

Consider the following reaction:
A - 2C
The average rate of appearance of C is given by O[C]/Ot. Comparing the rate of appearance of C and the rate of disappearance of A, we get O[C]/Ot = × (O[A]/Ot).

Accepted Answer

A)  +1/2 
B)  - 1/2 
C)  +2 
D)  +1 
E)  - 1 
A)  +1/2 
B)  - 1/2 
C)  +2 
D)  +1 
E)  - 1

Question 6

A catalyst can increase the rate of a reaction .

Accepted Answer

A)  by providing an alternative pathway with a lower activation energy 
B)  by lowering the overall activation energy (Ea) of the reaction 
C)  by lowering the activation energy of the reverse reaction 
D)  by changing the value of the frequency factor (
A)  
E)  All of these are ways that a catalyst might act to increase the rate of reaction. 
A)  by providing an alternative pathway with a lower activation energy 
B)  by lowering the overall activation energy (Ea) of the reaction 
C)  by lowering the activation energy of the reverse reaction 
D)  by changing the value of the frequency factor (
A)  
E)  All of these are ways that a catalyst might act to increase the rate of reaction.

Question 7

Which one of the following graphs shows the correct relationship between concentration and time for a reaction that is second order in [A]?

Accepted Answer

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

Question 8

Reaction rate data obey an equation devised by _ .

Accepted Answer

The answer of Reaction rate data obey an equation devised...

Question 9

The enzyme nitrogenase converts _ _ into _.

Accepted Answer

A)  nitrogen oxides, N2 and O2 
B)  nitroglycerine, nitric acid, and glycerine 
C)  ammonia, urea 
D)  CO and unburned hydrocarbons, H2O and CO2 
E)  nitrogen, ammonia 
A)  nitrogen oxides, N2 and O2 
B)  nitroglycerine, nitric acid, and glycerine 
C)  ammonia, urea 
D)  CO and unburned hydrocarbons, H2O and CO2 
E)  nitrogen, ammonia

Question 10

The rate constant for a second- order reaction is 0.13 M- 1s- 1. If the initial concentration of reactant is 0.26 mol/L, it takes s for the concentration to decrease to 0.13 mol/L.

Accepted Answer

A)  1.0 
B)  0.017 
C)  30 
D)  4.4 × 10- 3  
E)  0.50 
A)  1.0 
B)  0.017 
C)  30 
D)  4.4 × 10- 3  
E)  0.50

Question 11

The kinetics of the reaction below were studied and it was determined that the reaction rate did not change when the concentration of B was tripled. The reaction is order in B.
A + B → P

Accepted Answer

A)  zero 
B)  first 
C)  second 
D)  third 
E)  one- half 
A)  zero 
B)  first 
C)  second 
D)  third 
E)  one- half

Question 12

The graph shown below depicts the relationship between concentration and time for the following chemical reaction.
 
The slope of this line is equal to .

Accepted Answer

A)  ln[A]o  
B)  1/k 
C)  - k 
D)  - 1/k 
E)  k 
A)  ln[A]o  
B)  1/k 
C)  - k 
D)  - 1/k 
E)  k

Question 13

The concentration of S2O82- remaining at 400 s is _ M.

Accepted Answer

A)  +0.057 
B)  - 0.007 
C)  +0.015 
D)  +0.035 
E)  +0.045 
A)  +0.057 
B)  - 0.007 
C)  +0.015 
D)  +0.035 
E)  +0.045

Question 14

The concentration of reactants or products at any time during the reaction can be calculated from the integrated rate law.

Accepted Answer

A) True 
 B)False

Question 15

The rate of disappearance of HBr in the gas phase reaction 2HBr (g) → H2 (g) + Br2 (g)
Is 0.190 M s- 1 at 150°C. The rate of reaction is M s- 1.

Accepted Answer

A)  2.63 
B)  0.086 
C)  0.0361 
D)  0.095 
E)  0.380 
A)  2.63 
B)  0.086 
C)  0.0361 
D)  0.095 
E)  0.380

Question 16

In general, as temperature goes up, reaction rate .

Accepted Answer

A)  goes up if the reaction is endothermic 
B)  goes up if the reaction is exothermic 
C)  stays the same regardless of whether the reaction is exothermic or endothermic 
D)  goes up regardless of whether the reaction is exothermic or endothermic 
E)  stays the same if the reaction is first order 
A)  goes up if the reaction is endothermic 
B)  goes up if the reaction is exothermic 
C)  stays the same regardless of whether the reaction is exothermic or endothermic 
D)  goes up regardless of whether the reaction is exothermic or endothermic 
E)  stays the same if the reaction is first order

Question 17

Of the units below, are appropriate for a first- order reaction rate constant.

Accepted Answer

A)  s- 1 
B)  mol/L 
C)  L mol- 1 s- 1 
D)  M s- 1 
E)  .M- 1 s- 1 
A)  s- 1 
B)  mol/L 
C)  L mol- 1 s- 1 
D)  M s- 1 
E)  .M- 1 s- 1

Question 18

The data in the table below were obtained for the reaction:
2 ClOS1U1B12 S1U1B0(aq) + 2 OHS1U1P1- S1S1P0(aq) →ClOS1U1B13S1U1B0S1U1P1- S1S1P0(aq) + ClOS1U1B12S1U1B0S1U1P1- S1S1P0(aq) + HS1U1B12S1U1B0O (1)  
-What is the magnitude of the rate constant for the reaction?

Accepted Answer

A)  4.6 
B)  115 
C)  230 
D)  713 
E)  1.15 × 104 
A)  4.6 
B)  115 
C)  230 
D)  713 
E)  1.15 × 104

Question 19

At elevated temperatures, methylisonitrile (CH3NC) isomerizes to acetonitrile (CH3CN):
CH3NC (g)  →  CH3CN (g)
At the start of an experiment, there are 0.200 mol of reactant and 0 mol of product in the reaction vessel. After 25 min, 0.108 mol of reactant (CH3NC) remain. There are _ _ mol of product (CH3CN) in the reaction vessel.

Accepted Answer

A)  0.200 
B)  0.308 
C)  0.540 
D)  0.022 
E)  0.092 
A)  0.200 
B)  0.308 
C)  0.540 
D)  0.022 
E)  0.092

Question 20

The data in the table below were obtained for the reaction:
A + B → P  
-The magnitude of the rate constant is .

Accepted Answer

A)  38.0 
B)  0.278 
C)  13.2 
D)  2.21 
E)  42.0 
A)  38.0 
B)  0.278 
C)  13.2 
D)  2.21 
E)  42.0

Exam 14: Chemical Kinetics

Heterogeneous catalysts have different phases from reactants.

The reaction 2NO2 → 2NO + O2 Follows second- order kinetics. At 300°C, [NO2] drops from 0.0100- to 0.00650- M in 100 s. The rate constant for the reaction is _ M- 1s- 1.

At elevated temperatures, dinitrogen pentoxide decomposes to nitrogen dioxide and oxygen: 2N2O5(g) → 4NO2 (g) + O2 (g) When the rate of formation of NO2 is 5.5 × 10- 4 M/s, the rate of decomposition of N2O5 is M/s)

The average rate of disappearance of I- between 400 s and 800 s is M/s.

Consider the following reaction: A - 2C The average rate of appearance of C is given by O[C]/Ot. Comparing the rate of appearance of C and the rate of disappearance of A, we get O[C]/Ot = × (O[A]/Ot).

A catalyst can increase the rate of a reaction .

Which one of the following graphs shows the correct relationship between concentration and time for a reaction that is second order in [A]?

Reaction rate data obey an equation devised by _ .

The enzyme nitrogenase converts _ _ into _.

The rate constant for a second- order reaction is 0.13 M- 1s- 1. If the initial concentration of reactant is 0.26 mol/L, it takes s for the concentration to decrease to 0.13 mol/L.

The kinetics of the reaction below were studied and it was determined that the reaction rate did not change when the concentration of B was tripled. The reaction is order in B. A + B → P

The graph shown below depicts the relationship between concentration and time for the following chemical reaction. The slope of this line is equal to .

The concentration of S2O82- remaining at 400 s is _ M.

The concentration of reactants or products at any time during the reaction can be calculated from the integrated rate law.

The rate of disappearance of HBr in the gas phase reaction 2HBr (g) → H2 (g) + Br2 (g) Is 0.190 M s- 1 at 150°C. The rate of reaction is M s- 1.

In general, as temperature goes up, reaction rate .

Of the units below, are appropriate for a first- order reaction rate constant.

The data in the table below were obtained for the reaction: 2 ClO2 (aq) + 2 OH- (aq) →ClO3- (aq) + ClO2- (aq) + H2O (1) -What is the magnitude of the rate constant for the reaction?

The data in the table below were obtained for the reaction: A + B → P -The magnitude of the rate constant is .

Introduction: Matter and Measurement

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Stoichiometry: Calculations With Chemical Formulas and Equations

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Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

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Chemical Equilibrium

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Additional Aspects of Equilibria

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Chemical Thermodynamics

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The reaction 2NO₂→ 2NO + O₂ Follows second- order kinetics. At 300°C, [NO₂] drops from 0.0100- to 0.00650- M in 100 s. The rate constant for the reaction is _ M^-¹s^-¹.

At elevated temperatures, dinitrogen pentoxide decomposes to nitrogen dioxide and oxygen: 2N₂O₅(g) → 4NO₂(g) + O₂(g) When the rate of formation of NO₂is 5.5 × 10^-⁴M/s, the rate of decomposition of ^N2^O5 is M/s)

The average rate of disappearance of I^-between 400 s and 800 s is M/s.

The rate constant for a second- order reaction is 0.13 M^-¹s^-¹. If the initial concentration of reactant is 0.26 mol/L, it takes s for the concentration to decrease to 0.13 mol/L.

The concentration of S₂O₈²^-remaining at 400 s is _ M.

The rate of disappearance of HBr in the gas phase reaction 2HBr (g) → H₂(g) + Br₂(g) Is 0.190 M s^-¹at 150°C. The rate of reaction is M s^-¹.

The data in the table below were obtained for the reaction: 2 ClO₂(aq) + 2 OH^-(aq) →ClO₃^-(aq) + ClO₂^-(aq) + H₂O (1) -What is the magnitude of the rate constant for the reaction?