Question 1

Ammonium cyanate (NH4CNO)reacts to form urea (N H2CON H2).At 65°C the rate constant,k,is 3.60 L • mol-1 • s-1.What is the rate law for this reaction?

Accepted Answer

A) Rate = (3.60 L • mol-1 • s-1)[NH4CNO] 
B) Rate = (3.60 L • mol-1 • s-1)[NH4CNO]2 
C) Rate = (0.28 mol • L-1 • s-1)[NH4CNO] 
D) Rate = (0.28 mol • L-1 • s-1)[NH4CNO]2 
E) Rate = (3.60 L • mol-1 • s-1)[N H2CON H2]-1 
A) Rate = (3.60 L • mol-1 • s-1)[NH4CNO] 
B) Rate = (3.60 L • mol-1 • s-1)[NH4CNO]2 
C) Rate = (0.28 mol • L-1 • s-1)[NH4CNO] 
D) Rate = (0.28 mol • L-1 • s-1)[NH4CNO]2 
E) Rate = (3.60 L • mol-1 • s-1)[N H2CON H2]-1 B

Question 2

For the reaction BrO3- + 5Br- + 6H+ → 3Br2 + 3H2O at a particular time,-Δ[BrO3-]/Δt = 1.5 × 10-2 M/s.What is -Δ[Br-]/Δt at the same instant?

Accepted Answer

A) 13 M/s 
B) 7.5 × 10-2 M/s 
C) 1.5 × 10-2 M/s 
D) 3.0 × 10-3 M/s 
E) 330 M/s 
A) 13 M/s 
B) 7.5 × 10-2 M/s 
C) 1.5 × 10-2 M/s 
D) 3.0 × 10-3 M/s 
E) 330 M/s B

Question 3

For the reaction X + Y → Z,the reaction rate is found to depend only upon the concentration of X.A plot of 1/X versus time gives a straight line.   What is the rate law for this reaction?

Accepted Answer

A) rate = k [X] 
B) rate = k [X]2 
C) rate = k [X][Y] 
D) rate = k [X]2[Y] 
E) rate = k [X]2/[Y] 
A) rate = k [X] 
B) rate = k [X]2 
C) rate = k [X][Y] 
D) rate = k [X]2[Y] 
E) rate = k [X]2/[Y] B

Question 4

The following diagram represents the first-order decomposition of A to form X according to the following balanced chemical equation: A → X.Each sphere represents 1.0 mmol of atoms,and the volume of the box is 1.0 L.   What is the rate constant?

Accepted Answer

A) 0.019 s-1 
B) 0.046 s-1 
C) 0.067 s-1 
D) 15 s-1 
E) 17 s-1 
A) 0.019 s-1 
B) 0.046 s-1 
C) 0.067 s-1 
D) 15 s-1 
E) 17 s-1

Question 5

The _______________ is the equation relating the rate of the reaction to the concentration of molecule.

Accepted Answer

The answer of The _______________ is the equation relating the...

Question 6

Consider the following reaction 8A(g)+ 5B(g)→ 8C(g)+ 6D(g)
If [C] is increasing at the rate of 4.0 mol L-1 • s-1,at what rate is [B] changing?

Accepted Answer

A) -0.40 mol L-1• s-1 
B) -2.5 mol L-1• s-1 
C) -4.0 mol L-1• s-1 
D) -5.0 mol L-1• s-1 
E) -6.4 mol L-1• s-1 
A) -0.40 mol L-1• s-1 
B) -2.5 mol L-1• s-1 
C) -4.0 mol L-1• s-1 
D) -5.0 mol L-1• s-1 
E) -6.4 mol L-1• s-1

Question 7

Which is the correct unit for a first-order rate constant?

Accepted Answer

A) s-1 
B) M • s-1 
C) M • s 
D) M -1 • s-1 
E) M -2 • s-1 
A) s-1 
B) M • s-1 
C) M • s 
D) M -1 • s-1 
E) M -2 • s-1

Question 8

The reaction A + 2B → products was found to follow the rate law: rate = k[A]2[B].Predict by what factor the rate of reaction will increase when the concentration of A is doubled,the concentration of B is tripled,and the temperature remains constant.

Accepted Answer

A) 5 
B) 6 
C) 12 
D) 18 
E) None of these 
A) 5 
B) 6 
C) 12 
D) 18 
E) None of these

Question 9

The isomerization of methyl isocyanide,CH3NC → CH3CN,follows first-order kinetics.The half-lives were found to be 161 min at 199°C and 12.5 min at 230.°C.Calculate the activation energy for this reaction.(R = 8.314 J/mol • K)

Accepted Answer

A) 6.17 × 10-3 kJ/mol 
B) 31.4 kJ/mol 
C) 78.2 kJ/mol 
D) 124 kJ/mol 
E) 163 kJ/mol 
A) 6.17 × 10-3 kJ/mol 
B) 31.4 kJ/mol 
C) 78.2 kJ/mol 
D) 124 kJ/mol 
E) 163 kJ/mol

Question 10

What is the half-life for a first-order reaction?

Accepted Answer

A) t1/2 = k 
B) t1/2 = 1/k[A]o 
C) t1/2 = 0.693/k[A]o 
D) t1/2 = [A]o/2k 
E) t1/2 = 0.693/k 
A) t1/2 = k 
B) t1/2 = 1/k[A]o 
C) t1/2 = 0.693/k[A]o 
D) t1/2 = [A]o/2k 
E) t1/2 = 0.693/k

Question 11

The rate law for the reaction 3A → C is rate = 4.36 × 10-2 L• mol-1 • h-1[A]2 What is the half-life for the reaction if the initial concentration of A is 0.250 M?

Accepted Answer

A) 0.0109 h 
B) 0.0629 h 
C) 15.9 h 
D) 23.9 h 
E) 91.7 h 
A) 0.0109 h 
B) 0.0629 h 
C) 15.9 h 
D) 23.9 h 
E) 91.7 h

Question 12

What statement below best describes the graph representing the integrated first-order rate law?

Accepted Answer

A) A plot of [A]t vs.t yields a straight line with a negative slope equal to -k. 
B) A plot of 1/[A]t vs.t yields a straight line with a negative slope equal to k. 
C) A plot of ln[A]t vs.t yields a straight line with a positive slope equal to -k. 
D) A plot of ln[A]t vs.t yields a straight line with a negative slope equal to -k. 
E) A plot of 1/[A]t vs.t yields a straight line with a positive slope equal to k. 
A) A plot of [A]t vs.t yields a straight line with a negative slope equal to -k. 
B) A plot of 1/[A]t vs.t yields a straight line with a negative slope equal to k. 
C) A plot of ln[A]t vs.t yields a straight line with a positive slope equal to -k. 
D) A plot of ln[A]t vs.t yields a straight line with a negative slope equal to -k. 
E) A plot of 1/[A]t vs.t yields a straight line with a positive slope equal to k.

Question 13

A ________-__________________ is a reaction whose rate depends on the concentration of one of the reactants squared.

Accepted Answer

second-ord

Question 14

Tetrafluoroethylene,C2F4,can be converted to octafluorocyclobutane,which can be used as a refrigerant or an aerosol propellant.A plot of 1/[C2F4] vs.time gives a straight line with a slope of 0.0448 L •mol-1 • s-1.What is the rate law for this reaction?

Accepted Answer

A) Rate = 0.0448 (L • mol-1 • s-1)[C2F4] 
B) Rate = 22.3 (mol • L-1 • s)[C2F4] 
C) Rate = 0.0448 (L • mol-1 • s-1)[C2F4]2 
D) Rate = 22.3 (mol • L-1 • s)[C2F4]2 
E) Rate = 0.0448 s-1 [C2F4] 
A) Rate = 0.0448 (L • mol-1 • s-1)[C2F4] 
B) Rate = 22.3 (mol • L-1 • s)[C2F4] 
C) Rate = 0.0448 (L • mol-1 • s-1)[C2F4]2 
D) Rate = 22.3 (mol • L-1 • s)[C2F4]2 
E) Rate = 0.0448 s-1 [C2F4]

Question 15

What is the name given for the study of how fast reactions take place?

Accepted Answer

A) Reaction rate 
B) Activation energy 
C) Chemical kinetics 
D) Reactivity 
E) Half-life 
A) Reaction rate 
B) Activation energy 
C) Chemical kinetics 
D) Reactivity 
E) Half-life

Question 16

For a zeroth-order reaction,if the concentration of reactant A is plotted vs.time,which corresponds to the slope of this plot?

Accepted Answer

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

Question 17

The ____________________ is the name given to the sequence of steps that sum to give the overall reaction.

Accepted Answer

The answer of The ____________________ is the name given to...

Question 18

When the reaction A → B + C is studied,a plot 1/[A]t vs.time gives a straight line with a positive slope.What is the order of the reaction with respect to A?

Accepted Answer

A) Zero 
B) First 
C) Second 
D) Third 
E) More information is needed to determine the order. 
A) Zero 
B) First 
C) Second 
D) Third 
E) More information is needed to determine the order.

Question 19

The units of the rate of reaction depend on the order of the reaction.

Accepted Answer

A) True 
 B)False

Question 20

What is the integrated rate law for a zeroth-order reaction?

Accepted Answer

A) rate = k[A]t 
B)    
C)    
D)    
E)    
A) rate = k[A]t 
B)    
C)    
D)    
E)

Exam 14: Chemical Kinetics

Ammonium cyanate (NH4CNO)reacts to form urea (N H2CON H2).At 65°C the rate constant,k,is 3.60 L • mol-1 • s-1.What is the rate law for this reaction?

For the reaction BrO3- + 5Br- + 6H+ → 3Br2 + 3H2O at a particular time,-Δ[BrO3-]/Δt = 1.5 × 10-2 M/s.What is -Δ[Br-]/Δt at the same instant?

For the reaction X + Y → Z,the reaction rate is found to depend only upon the concentration of X.A plot of 1/X versus time gives a straight line. What is the rate law for this reaction?

The following diagram represents the first-order decomposition of A to form X according to the following balanced chemical equation: A → X.Each sphere represents 1.0 mmol of atoms,and the volume of the box is 1.0 L. What is the rate constant?

The _______________ is the equation relating the rate of the reaction to the concentration of molecule.

Consider the following reaction 8A(g)+ 5B(g)→ 8C(g)+ 6D(g) If [C] is increasing at the rate of 4.0 mol L-1 • s-1,at what rate is [B] changing?

Which is the correct unit for a first-order rate constant?

The reaction A + 2B → products was found to follow the rate law: rate = k[A]2[B].Predict by what factor the rate of reaction will increase when the concentration of A is doubled,the concentration of B is tripled,and the temperature remains constant.

The isomerization of methyl isocyanide,CH3NC → CH3CN,follows first-order kinetics.The half-lives were found to be 161 min at 199°C and 12.5 min at 230.°C.Calculate the activation energy for this reaction.(R = 8.314 J/mol • K)

What is the half-life for a first-order reaction?

The rate law for the reaction 3A → C is rate = 4.36 × 10-2 L• mol-1 • h-1[A]2 What is the half-life for the reaction if the initial concentration of A is 0.250 M?

What statement below best describes the graph representing the integrated first-order rate law?

A ________-__________________ is a reaction whose rate depends on the concentration of one of the reactants squared.

Tetrafluoroethylene,C2F4,can be converted to octafluorocyclobutane,which can be used as a refrigerant or an aerosol propellant.A plot of 1/[C2F4] vs.time gives a straight line with a slope of 0.0448 L •mol-1 • s-1.What is the rate law for this reaction?

What is the name given for the study of how fast reactions take place?

For a zeroth-order reaction,if the concentration of reactant A is plotted vs.time,which corresponds to the slope of this plot?

The ____________________ is the name given to the sequence of steps that sum to give the overall reaction.

When the reaction A → B + C is studied,a plot 1/[A]t vs.time gives a straight line with a positive slope.What is the order of the reaction with respect to A?

The units of the rate of reaction depend on the order of the reaction.

What is the integrated rate law for a zeroth-order reaction?

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Reactions in Aqueous Solutions

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Filters

Ammonium cyanate (NH₄CNO)reacts to form urea (N H₂CON H₂).At 65°C the rate constant,k,is 3.60 L • mol^-1 • s^-1.What is the rate law for this reaction?

For the reaction BrO₃^- + 5Br^- + 6H⁺ → 3Br² + 3H₂O at a particular time,-Δ[BrO₃^-]/Δt = 1.5 × 10^-2 M/s.What is -Δ[Br^-]/Δt at the same instant?

Consider the following reaction 8A(g)+ 5B(g)→ 8C(g)+ 6D(g) If [C] is increasing at the rate of 4.0 mol L^-1 • s^-1,at what rate is [B] changing?

The reaction A + 2B → products was found to follow the rate law: rate = k[A]²[B].Predict by what factor the rate of reaction will increase when the concentration of A is doubled,the concentration of B is tripled,and the temperature remains constant.

The isomerization of methyl isocyanide,CH₃NC → CH₃CN,follows first-order kinetics.The half-lives were found to be 161 min at 199°C and 12.5 min at 230.°C.Calculate the activation energy for this reaction.(R = 8.314 J/mol • K)

The rate law for the reaction 3A → C is rate = 4.36 × 10^-2 L• mol^-1 • h^-1[A]² What is the half-life for the reaction if the initial concentration of A is 0.250 M?

A -__________ is a reaction whose rate depends on the concentration of one of the reactants squared.

Tetrafluoroethylene,C₂F₄,can be converted to octafluorocyclobutane,which can be used as a refrigerant or an aerosol propellant.A plot of 1/[C₂F₄] vs.time gives a straight line with a slope of 0.0448 L •mol^-1 • s^-1.What is the rate law for this reaction?