Question 1

The rate constant for a second-order reaction is 0.13     .If the initial concentration of reactant is   it takes ________ s for the concentration to decrease to

Accepted Answer

A) 0.017 
B) 1.4 
C) 14 
D) 80. 
E) 10. 
A) 0.017 
B) 1.4 
C) 14 
D) 80. 
E) 10.

Question 2

Which of the following is true?

Accepted Answer

A) If we know that a reaction is an elementary reaction, then we know its rate law. 
B) The rate-determining step of a reaction is the rate of the fastest elementary step of its mechanism. 
C) Since intermediate compounds can be formed, the chemical equations for the elementary reactions in a multistep mechanism do not always have to add to give the chemical equation of the overall process. 
D) In a reaction mechanism, an intermediate is identical to an activated complex. 
E) All of the above statements are true. 
A) If we know that a reaction is an elementary reaction, then we know its rate law. 
B) The rate-determining step of a reaction is the rate of the fastest elementary step of its mechanism. 
C) Since intermediate compounds can be formed, the chemical equations for the elementary reactions in a multistep mechanism do not always have to add to give the chemical equation of the overall process. 
D) In a reaction mechanism, an intermediate is identical to an activated complex. 
E) All of the above statements are true.

Question 3

According to the collision model,reaction rates are affected by reactant ________ and ________.

Accepted Answer

concentrat

Question 4

A reaction was found to be zero order in A.Increasing the concentration of A by a factor of 3 will cause the reaction rate to ________.

Accepted Answer

A) remain constant 
B) increase by a factor of 27 
C) increase by a factor of 9 
D) triple 
E) decrease by a factor of the cube root of 3 
A) remain constant 
B) increase by a factor of 27 
C) increase by a factor of 9 
D) triple 
E) decrease by a factor of the cube root of 3

Question 5

Which of the following statements describes why nitrogen fixation is a difficult process?

Accepted Answer

A) there is so little nitrogen in the atmosphere 
B) nitrogen is very unreactive, largely due to its triple bond 
C) nitrogen exists in the atmosphere primarily as its oxides which are very unreactive 
D) of the high polarity of nitrogen molecules preventing them from dissolving in biological fluids, such as those inside cells 
E) of the extreme toxicity of nitrogen 
A) there is so little nitrogen in the atmosphere 
B) nitrogen is very unreactive, largely due to its triple bond 
C) nitrogen exists in the atmosphere primarily as its oxides which are very unreactive 
D) of the high polarity of nitrogen molecules preventing them from dissolving in biological fluids, such as those inside cells 
E) of the extreme toxicity of nitrogen

Question 6

Define a homogeneous catalyst.

Accepted Answer

A CATALYST THAT IS P

Question 7

What is the concentration (M)of S2O82- remaining at 1200 s?

Accepted Answer

A) +0.035 
B) +0.038 
C) -0.038 
D) +0.012 
E) -0.012 
A) +0.035 
B) +0.038 
C) -0.038 
D) +0.012 
E) -0.012

Question 8

Heterogeneous catalysts have different phases from reactants.

Accepted Answer

A) True 
 B)False

Question 9

What is the rate constant (s-1)for this reaction?

Accepted Answer

A) 3.0 × 10-2 
B) 14 
C) 0.46 
D) 4.0 × 102 
E) 7.8 × 10-2 
A) 3.0 × 10-2 
B) 14 
C) 0.46 
D) 4.0 × 102 
E) 7.8 × 10-2

Question 10

A first-order reaction has a rate constant of 0.33   .It takes ________ min for the reactant concentration to decrease from 0.13 M to 0.066 M.

Accepted Answer

A) 0.085 
B) 0.13 
C) 0.89 
D) 2.4 
E) 2.1 
A) 0.085 
B) 0.13 
C) 0.89 
D) 2.4 
E) 2.1

Question 11

What is the rate constant (   )of a first-order process that has a half-life of 550 s?

Accepted Answer

A) 3.81 × 102 
B) 7.94 × 102 
C) -9.09 × 10-4 
D) 1.26 × 10-3 
E) 1.82 × 10-3 
A) 3.81 × 102 
B) 7.94 × 102 
C) -9.09 × 10-4 
D) 1.26 × 10-3 
E) 1.82 × 10-3

Question 12

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

Accepted Answer

A) M-2s-1 
B) M s-1 
C) s-1 
D) M-1s-1 
E) mol/L 
A) M-2s-1 
B) M s-1 
C) s-1 
D) M-1s-1 
E) mol/L

Question 13

A possible mechanism for the overall reaction Br2 (g)+ 2NO (g)→ 2NOBr (g)
Is
Step 1)NO (g)+ Br2 (g)   NOBr2 (g)(fast)
Step 2)NOBr2 (g)+ NO (g)   2NOBr (slow)
What is the rate determining step for this reaction?

Accepted Answer

A) step 2 
B) reverse of step 1 
C) both steps 1 and 2 
D) step 1 
E) reverse of step 2 
A) step 2 
B) reverse of step 1 
C) both steps 1 and 2 
D) step 1 
E) reverse of step 2

Question 14

The average rate disappearance of A between 20 s and 30 s is ________ mol/s.

Accepted Answer

A) 5.0 × 10-4 
B) 1.6 × 10-2 
C) 1.5 × 10-3 
D) 670 
E) 0.15 
A) 5.0 × 10-4 
B) 1.6 × 10-2 
C) 1.5 × 10-3 
D) 670 
E) 0.15

Question 15

The average rate of disappearance of I- between 400.0 s and 800.0 s is ________ M/s.

Accepted Answer

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

Question 16

A particular first-order reaction has a rate constant of 1.35 ×     at 25.0 °C.What is the magnitude of k at

Accepted Answer

A) 1.92 × 103 
B) 1.95 × 104 
C) 358 
D) 3.48 × 1073 
E) 1.35 ×   
A) 1.92 × 103 
B) 1.95 × 104 
C) 358 
D) 3.48 × 1073 
E) 1.35 ×

Question 17

The mechanism for formation of the product X is: A + B → C + D (slow)
B + D → X (fast)
The intermediate reactant in the reaction is ________.

Accepted Answer

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

Question 18

Of the following,only ________ is a valid unit for reaction rate.

Accepted Answer

A) M/s 
B) mol/g 
C) mmol/mL 
D) g/L 
E) atm/g 
A) M/s 
B) mol/g 
C) mmol/mL 
D) g/L 
E) atm/g

Question 19

Units of the rate constant of a reaction are independent of the overall reaction order.

Accepted Answer

A) True 
 B)False

Question 20

The overall order of a reaction is 1.The units of the rate constant for the reaction are ________.

Accepted Answer

A) M/s 
B) M-1s-1 
C) 1/s 
D) 1/M 
E) s/M2 
A) M/s 
B) M-1s-1 
C) 1/s 
D) 1/M 
E) s/M2

Exam 14: Chemical Kinetics

The rate constant for a second-order reaction is 0.13 .If the initial concentration of reactant is it takes ________ s for the concentration to decrease to

Which of the following is true?

According to the collision model,reaction rates are affected by reactant ________ and ________.

A reaction was found to be zero order in A.Increasing the concentration of A by a factor of 3 will cause the reaction rate to ________.

Which of the following statements describes why nitrogen fixation is a difficult process?

Define a homogeneous catalyst.

What is the concentration (M)of S2O82- remaining at 1200 s?

Heterogeneous catalysts have different phases from reactants.

What is the rate constant (s-1)for this reaction?

A first-order reaction has a rate constant of 0.33 .It takes ________ min for the reactant concentration to decrease from 0.13 M to 0.066 M.

What is the rate constant ( )of a first-order process that has a half-life of 550 s?

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

A possible mechanism for the overall reaction Br2 (g)+ 2NO (g)→ 2NOBr (g) Is Step 1)NO (g)+ Br2 (g) NOBr2 (g)(fast) Step 2)NOBr2 (g)+ NO (g) 2NOBr (slow) What is the rate determining step for this reaction?

The average rate disappearance of A between 20 s and 30 s is ________ mol/s.

The average rate of disappearance of I- between 400.0 s and 800.0 s is ________ M/s.

A particular first-order reaction has a rate constant of 1.35 × at 25.0 °C.What is the magnitude of k at

The mechanism for formation of the product X is: A + B → C + D (slow) B + D → X (fast) The intermediate reactant in the reaction is ________.

Of the following,only ________ is a valid unit for reaction rate.

Units of the rate constant of a reaction are independent of the overall reaction order.

The overall order of a reaction is 1.The units of the rate constant for the reaction are ________.

Introduction: Matter, energy, and Measurement

Atoms, molecules, and Ions

Chemical Reactions and Reaction Stoichiometry

Reactions in Aqueous Solution

Thermochemistry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

According to the collision model,reaction rates are affected by reactant and .

What is the concentration (M)of S₂O₈^2- remaining at 1200 s?

What is the rate constant (s^-1)for this reaction?

A possible mechanism for the overall reaction Br₂ (g)+ 2NO (g)→ 2NOBr (g) Is Step 1)NO (g)+ Br₂(g) NOBr₂ (g)(fast) Step 2)NOBr₂(g)+ NO (g) 2NOBr (slow) What is the rate determining step for this reaction?

The average rate of disappearance of I^- between 400.0 s and 800.0 s is ________ M/s.