Question 1

Given the following rate law,how does the rate of reaction change if the concentration of X is doubled?
Rate = k [X]2[Y]3

Accepted Answer

A)  The rate of reaction will increase by a factor of 9. 
B)  The rate of reaction will increase by a factor of 5. 
C)  the rate of reaction will increase by a factor of 6. 
D)  The rate of reaction will increase by a factor of 4. 
E)  The rate of reaction will remain unchanged. 
A)  The rate of reaction will increase by a factor of 9. 
B)  The rate of reaction will increase by a factor of 5. 
C)  the rate of reaction will increase by a factor of 6. 
D)  The rate of reaction will increase by a factor of 4. 
E)  The rate of reaction will remain unchanged.

Question 2

Given the following proposed mechanism,predict the rate law for the overall reaction. A2 + 2B → 2AB (overall reaction)
Mechanism
A2 ⇌ 2A fast
A + B → AB slow

Accepted Answer

A)  Rate = k[A][B] 
B)  Rate = k[A2][B] 
C)  Rate = k[A2][B]1/2 
D)  Rate = k[A2] 
E)  Rate = k [A2]1/2[B] 
A)  Rate = k[A][B] 
B)  Rate = k[A2][B] 
C)  Rate = k[A2][B]1/2 
D)  Rate = k[A2] 
E)  Rate = k [A2]1/2[B]

Question 3

The first-order rearrangement of CH3NC is measured to have a rate constant of 3.61 × 10-15 s-1 at 298 K and a rate constant of 8.66 × 10-7 s-1 at 425 K.Determine the activation energy for this reaction.

Accepted Answer

A)  160. kJ/mol 
B)  240. kJ/mol 
C)  417 kJ/mol 
D)  127 kJ/mol 
E)  338 kJ/mol 
A)  160. kJ/mol 
B)  240. kJ/mol 
C)  417 kJ/mol 
D)  127 kJ/mol 
E)  338 kJ/mol

Question 4

The first-order decay of radon has a half-life of 3.823 days.How many grams of radon remain after 7.22 days if the sample initially weighs 250.0 grams?

Accepted Answer

A)  4.21 g 
B)  183 g 
C)  54.8 g 
D)  76.3 g 
E)  67.5 g 
A)  4.21 g 
B)  183 g 
C)  54.8 g 
D)  76.3 g 
E)  67.5 g

Question 5

The reaction that occurs in a Breathalyzer,a device used to determine the alcohol level in a person's bloodstream,is given below.If the rate of appearance of Cr2(SO4)3 is 1.64 mol/min at a particular moment,what is the rate of disappearance of C2H6O at that moment?

Accepted Answer

A)  0.547 mol/min 
B)  1.09 mol/min 
C)  2.46 mol/min 
D)  4.92 mol/min 
A)  0.547 mol/min 
B)  1.09 mol/min 
C)  2.46 mol/min 
D)  4.92 mol/min

Question 6

Given the following balanced equation,determine the rate of reaction with respect to [SO2]. 2 SO2(g)+ O2(g)→ 2 SO3(g)

Accepted Answer

A)  Rate = -     
B)  Rate = +     
C)  Rate = -   
D)  Rate = +   
E)  It is not possible to determine without more information. 
A)  Rate = -     
B)  Rate = +     
C)  Rate = -   
D)  Rate = +   
E)  It is not possible to determine without more information.

Question 7

A reaction occurs via the following sequence of elementary steps.What is the reaction intermediate?
1st step: A + 2B → 2C
2nd step: 2C → D

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  There is no intermediate. 
A)  A 
B)  B 
C)  C 
D)  D 
E)  There is no intermediate.

Question 8

A reaction is found to have an activation energy of 38.0 kJ/mol.If the rate constant for this reaction is 1.60 × 102 M-1s-1 at 249 K,what is the rate constant at 436 K?

Accepted Answer

A)  2.38 × 105 M-1s-1 
B)  1.26 × 103 M-1s-1 
C)  7.94 × 104 M-1s-1 
D)  4.20 × 105 M-1s-1 
E)  3.80 × 104 M-1s-1 
A)  2.38 × 105 M-1s-1 
B)  1.26 × 103 M-1s-1 
C)  7.94 × 104 M-1s-1 
D)  4.20 × 105 M-1s-1 
E)  3.80 × 104 M-1s-1

Question 9

The rate of disappearance of HBr in the gas phase reaction 2HBr(g)→ H2(g)+ Br2(g)
Is 0.301 M   at 150°C.The rate of appearance of   is ________ M   .

Accepted Answer

A)  1.66 
B)  0.151 
C)  0.0906 
D)  0.602 
E)  0.549 
A)  1.66 
B)  0.151 
C)  0.0906 
D)  0.602 
E)  0.549

Question 10

The following reaction is first order,C2H6 → 2 CH3.If the rate constant is equal to 5.5 × 10-4 s-1 at 1000 K,how long will it take for 0.35 mol of C2H6 in a 1.00 L container to decrease to 0.20 mol in the same container?

Accepted Answer

A)  4.5 min 
B)  17 min 
C)  53 min 
D)  65 min 
A)  4.5 min 
B)  17 min 
C)  53 min 
D)  65 min

Question 11

Given the following balanced equation,determine the rate of reaction with respect to [O2]. 2 SO2(g)+ O2(g)→ 2 SO3(g)

Accepted Answer

A)  Rate = -     
B)  Rate = +     
C)  Rate = -   
D)  Rate = +   
E)  It is not possible to determine without more information. 
A)  Rate = -     
B)  Rate = +     
C)  Rate = -   
D)  Rate = +   
E)  It is not possible to determine without more information.

Question 12

Nitrogen dioxide decomposes at 300°C via a second-order process to produce nitrogen monoxide and oxygen according to the following chemical equation. 2 NO2(g)→ 2 NO(g)+ O2(g).
A sample of NO2(g)is initially placed in a 2.50-L reaction vessel at 300°C.If the half-life and the rate constant at 300°C are 11 seconds and 0.54 M-1 s-1,respectively,how many moles of NO2 were in the original sample?

Accepted Answer

A)  0.17 mol 
B)  0.42 mol 
C)  5.9 mol 
D)  15 mol 
A)  0.17 mol 
B)  0.42 mol 
C)  5.9 mol 
D)  15 mol

Question 13

What are the units of k in a second order reaction?

Accepted Answer

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

Question 14

Which rate law is termolecular?

Accepted Answer

A)  rate = k[A][B]2 
B)  rate = k [A][B]3 
C)  rate = k [A]5 
D)  rate = k [A][B][C][D] 
E)  rate = k [A]2 
A)  rate = k[A][B]2 
B)  rate = k [A][B]3 
C)  rate = k [A]5 
D)  rate = k [A][B][C][D] 
E)  rate = k [A]2

Question 15

Given the following balanced equation,determine the rate of reaction with respect to [Cl2].If the rate of Cl2 loss is 4.24 × 10-2 M/s,what is the rate of formation of NO?
2 NO(g)+ Cl2(g)→ 2 NOCl(g)

Accepted Answer

A)  4.24 × 10-2 M/s 
B)  2.12 × 10-2 M/s 
C)  1.06 × 10-1 M/s 
D)  8.48 × 10-2 M/s 
E)  1.61 × 10-2 M/s 
A)  4.24 × 10-2 M/s 
B)  2.12 × 10-2 M/s 
C)  1.06 × 10-1 M/s 
D)  8.48 × 10-2 M/s 
E)  1.61 × 10-2 M/s

Question 16

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 appearance of H2 is ________ M s-1.

Accepted Answer

A)  2.63 
B)  0.0950 
C)  0.0361 
D)  0.380 
E)  0.0860 
A)  2.63 
B)  0.0950 
C)  0.0361 
D)  0.380 
E)  0.0860

Question 17

How many half-lives are required for the concentration of reactant to decrease to 12.5% of its original value?

Accepted Answer

A)  3 
B)  2 
C)  2.5 
D)  2.75 
E)  8 
A)  3 
B)  2 
C)  2.5 
D)  2.75 
E)  8

Question 18

What are the units of k in the following rate law?
Rate = k[X]2[Y]2

Accepted Answer

A)    
B)    
C)  M2 s 
D)    
E)    
A)    
B)    
C)  M2 s 
D)    
E)

Question 19

A reaction has a rate constant of 6.0 × 10-3 L2 mol-2 s-1 at 10°C.If its activation energy is 84 kJ/mol,what is the value of the rate constant at 50°C?

Accepted Answer

A)  4.8 L2mol-2s-1 
B)  0.50 L2mol-2s-1 
C)  0.018 L2mol-2s-1 
D)  8.2 × 103 L2mol-2s-1 
E)  0.84 L2mol-2s-1 
A)  4.8 L2mol-2s-1 
B)  0.50 L2mol-2s-1 
C)  0.018 L2mol-2s-1 
D)  8.2 × 103 L2mol-2s-1 
E)  0.84 L2mol-2s-1

Question 20

Which of the following reactions would you predict to have the smallest orientation factor?

Accepted Answer

A)  X2 + Y2 → 2 XY 
B)  NOCl2 + NO → 2 NOCl 
C)  N2 + O2 → 2 NO 
D)  N + O2 → NO2 
E)  All of these reactions should have nearly identical orientation factors. 
A)  X2 + Y2 → 2 XY 
B)  NOCl2 + NO → 2 NOCl 
C)  N2 + O2 → 2 NO 
D)  N + O2 → NO2 
E)  All of these reactions should have nearly identical orientation factors.

Exam 15: Chemical Kinetics

Given the following rate law,how does the rate of reaction change if the concentration of X is doubled? Rate = k [X]2[Y]3

Given the following proposed mechanism,predict the rate law for the overall reaction. A2 + 2B → 2AB (overall reaction) Mechanism A2 ⇌ 2A fast A + B → AB slow

The first-order rearrangement of CH3NC is measured to have a rate constant of 3.61 × 10-15 s-1 at 298 K and a rate constant of 8.66 × 10-7 s-1 at 425 K.Determine the activation energy for this reaction.

The first-order decay of radon has a half-life of 3.823 days.How many grams of radon remain after 7.22 days if the sample initially weighs 250.0 grams?

The reaction that occurs in a Breathalyzer,a device used to determine the alcohol level in a person's bloodstream,is given below.If the rate of appearance of Cr2(SO4)3 is 1.64 mol/min at a particular moment,what is the rate of disappearance of C2H6O at that moment?

Given the following balanced equation,determine the rate of reaction with respect to [SO2]. 2 SO2(g)+ O2(g)→ 2 SO3(g)

A reaction occurs via the following sequence of elementary steps.What is the reaction intermediate? 1st step: A + 2B → 2C 2nd step: 2C → D

A reaction is found to have an activation energy of 38.0 kJ/mol.If the rate constant for this reaction is 1.60 × 102 M-1s-1 at 249 K,what is the rate constant at 436 K?

The rate of disappearance of HBr in the gas phase reaction 2HBr(g)→ H2(g)+ Br2(g) Is 0.301 M at 150°C.The rate of appearance of is ________ M .

The following reaction is first order,C2H6 → 2 CH3.If the rate constant is equal to 5.5 × 10-4 s-1 at 1000 K,how long will it take for 0.35 mol of C2H6 in a 1.00 L container to decrease to 0.20 mol in the same container?

Given the following balanced equation,determine the rate of reaction with respect to [O2]. 2 SO2(g)+ O2(g)→ 2 SO3(g)

What are the units of k in a second order reaction?

Which rate law is termolecular?

Given the following balanced equation,determine the rate of reaction with respect to [Cl2].If the rate of Cl2 loss is 4.24 × 10-2 M/s,what is the rate of formation of NO? 2 NO(g)+ Cl2(g)→ 2 NOCl(g)

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 appearance of H2 is ________ M s-1.

How many half-lives are required for the concentration of reactant to decrease to 12.5% of its original value?

What are the units of k in the following rate law? Rate = k[X]2[Y]2

A reaction has a rate constant of 6.0 × 10-3 L2 mol-2 s-1 at 10°C.If its activation energy is 84 kJ/mol,what is the value of the rate constant at 50°C?

Which of the following reactions would you predict to have the smallest orientation factor?

Essentials: Units, Measurements, and Problem Solving

Atoms

The Quantum Mechanical Model of the Atom

Periodic Properties of the Elements

Molecules and Compounds

Chemical Bonding I

Chemical Bonding Ii

Chemical Reactions and Chemical Quantities

Introduction to Solutions and Aqueous Reactions

Thermochemistry

Gases

Liquids, Solids, and Intermolecular Forces

Crystalline Solids and Modern Materials

Solutions

Chemical Equilibrium

Acids and Bases

Aqueous Ionic Equilibrium

Free Energy and Thermodynamics

Electrochemistry

Radioactivity and Nuclear Chemistry

Organic Chemistry

Transition Metals and Coordination Compounds

Filters

Given the following rate law,how does the rate of reaction change if the concentration of X is doubled? Rate = k [X]²[Y]³

Given the following proposed mechanism,predict the rate law for the overall reaction. A₂ + 2B → 2AB (overall reaction) Mechanism A₂ ⇌ 2A fast A + B → AB slow

The first-order rearrangement of CH₃NC is measured to have a rate constant of 3.61 × 10^-15 s^-1 at 298 K and a rate constant of 8.66 × 10^-7 s^-1 at 425 K.Determine the activation energy for this reaction.

The reaction that occurs in a Breathalyzer,a device used to determine the alcohol level in a person's bloodstream,is given below.If the rate of appearance of Cr₂(SO₄)₃ is 1.64 mol/min at a particular moment,what is the rate of disappearance of C₂H₆O at that moment?

Given the following balanced equation,determine the rate of reaction with respect to [SO₂]. 2 SO₂(g)+ O₂(g)→ 2 SO₃(g)

A reaction occurs via the following sequence of elementary steps.What is the reaction intermediate? 1^st step: A + 2B → 2C 2^nd step: 2C → D

A reaction is found to have an activation energy of 38.0 kJ/mol.If the rate constant for this reaction is 1.60 × 10² M^-1s^-1 at 249 K,what is the rate constant at 436 K?

The rate of disappearance of HBr in the gas phase reaction 2HBr(g)→ H₂(g)+ Br₂(g) Is 0.301 M at 150°C.The rate of appearance of is ________ M .

The following reaction is first order,C₂H₆ → 2 CH₃.If the rate constant is equal to 5.5 × 10^-4 s^-1 at 1000 K,how long will it take for 0.35 mol of C₂H₆ in a 1.00 L container to decrease to 0.20 mol in the same container?

Given the following balanced equation,determine the rate of reaction with respect to [O₂]. 2 SO₂(g)+ O₂(g)→ 2 SO₃(g)

Given the following balanced equation,determine the rate of reaction with respect to [Cl₂].If the rate of Cl₂ loss is 4.24 × 10^-2 M/s,what is the rate of formation of NO? 2 NO(g)+ Cl₂(g)→ 2 NOCl(g)

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 appearance of H₂ is ________ M s^-1.

What are the units of k in the following rate law? Rate = k[X]²[Y]²

A reaction has a rate constant of 6.0 × 10^-3 L² mol^-2 s^-1 at 10°C.If its activation energy is 84 kJ/mol,what is the value of the rate constant at 50°C?