Question 1

What is the half-life of a second order reaction?

Accepted Answer

The answer of What is the half-life of a second...

Question 2

The HBr synthesis is thought to involve the following reactions:
 
 The chain termination reactions in this mechanism are reactions

Accepted Answer

A) 3,4,and 5. 
B) 4 and 5. 
C) 4,5,and 6. 
D) 6. 
E) 3 and 4. 
A) 3,4,and 5. 
B) 4 and 5. 
C) 4,5,and 6. 
D) 6. 
E) 3 and 4.

Question 3

For the reaction
2NO(g)+ 2H2(g)$\rightarrow$ N2(g)+ 2H2O(g)
the following data were collected.
 
What is the rate law for this reaction?

Accepted Answer

rate = k[H

Question 4

If the rate of reaction increases by a factor of 9.6 when the concentration of reactant increases by a factor of 3.1,the order of the reaction with respect to this reactant is

Accepted Answer

A) 1.5 
B) 3 
C) 4 
D) 2 
E) 1 
A) 1.5 
B) 3 
C) 4 
D) 2 
E) 1

Question 5

For the elementary reaction A + 2B $\rightarrow$ products,rate = k[A][B].

Accepted Answer

A) True 
 B)False

Question 6

For the reaction cyclopropane $\rightarrow$   propene
A plot of ln[cyclopropane] vs time in seconds gives a straight line with slope -4.1 * 10-3 s-1 at 550S1U1P1$\circ$S1S1P0C.What is the rate constant for this reaction?

Accepted Answer

A) 3.9 * 10-2 s-1 
B) 8.2 * 10-3 s-1 
C) 4.1 * 10-3 s-1 
D) 1.8 * 10-3 s-1 
E) 2.1 * 10-3 s-1 
A) 3.9 * 10-2 s-1 
B) 8.2 * 10-3 s-1 
C) 4.1 * 10-3 s-1 
D) 1.8 * 10-3 s-1 
E) 2.1 * 10-3 s-1

Question 7

If the average rate of decomposition of PH3(g)is 3.2 (mol PH3).L-1.min-1 for the reaction 2PH3(g)$\rightarrow$ 2P(g)+ 3H2(g),the unique average reaction rate is

Accepted Answer

A) 3.2 mol.-1.min-1. 
B) 2.1 mol.-1.min-1 
C) 1.6 mol.-1.min-1 
D) 4.8 mol.-1.min-1 
E) 6.4 mol.-1.min-1 
A) 3.2 mol.-1.min-1. 
B) 2.1 mol.-1.min-1 
C) 1.6 mol.-1.min-1 
D) 4.8 mol.-1.min-1 
E) 6.4 mol.-1.min-1

Question 8

An elementary process has an activation energy of 92 kJ/mol.If the enthalpy change for the reaction is -62 kJ/mol,what is the activation energy for the reverse reaction?

Accepted Answer

A) 154 kJ/mol 
B) 62 kJ/mol 
C) 92 kJ/mol 
D) 30 kJ/mol 
A) 154 kJ/mol 
B) 62 kJ/mol 
C) 92 kJ/mol 
D) 30 kJ/mol

Question 9

For a given first-order reaction,after 2.00 min,20% of the reactants remain.Calculate the rate constant for the reaction.

Accepted Answer

A) 0.0134 s-1  
B) 0.000808 s-1  
C) 74.6 s-1  
D) 0.00582 s-1  
E) 0.00186 s-1  
A) 0.0134 s-1  
B) 0.000808 s-1  
C) 74.6 s-1  
D) 0.00582 s-1  
E) 0.00186 s-1

Question 10

The reaction 2A + B $\rightarrow$ D + E has the rate law,rate = a[A]2[B]/(b + c[A])where a,b,and c are constants.The following mechanism has been proposed for this reaction.
A + B →
k1,k-1
I + A $\rightarrow$ D + E
k2
I is an unstable intermediate present in minute concentrations.Show that this mechanism leads to the observed rate law and evaluate the constants a,b,and c in terms of the rate constants k1,k-1,and k2.

Accepted Answer

a = k₁k₂

Question 11

The concentration-time curves for two sets of reactions,A/B and C/D,are:   
Which set of reactions has the largest rate constant?

Accepted Answer

The answer of The concentration-time curves for two sets of...

Question 12

Consider the dimerization reaction below: 
2A$\rightarrow$  A2
Rate = k[A]2
When the initial concentration of A is 2.0 M,it requires 30 min for 60% of A to react.Calculate the rate constant.

Accepted Answer

A) 1.1 * 10-3 M-1.s-1  
B) 3.2 * 10-4 M-1.s-1  
C) 5.0 * 10-4 M-1.s-1  
D) 1.9* 10-4 M-1.s-1  
E) 4.2 * 10-4 M-1.s-1  
A) 1.1 * 10-3 M-1.s-1  
B) 3.2 * 10-4 M-1.s-1  
C) 5.0 * 10-4 M-1.s-1  
D) 1.9* 10-4 M-1.s-1  
E) 4.2 * 10-4 M-1.s-1

Question 13

A first-order reaction has a half-life of 1.10 s.If the initial concentration of reactant is 0.384 M,how long will it take for the reactant concentration to reach 0.00100 M?

Accepted Answer

A) 9.45 s 
B) 0.106 s 
C) 4.10 s 
D) 1.52 s 
E) 0.244 s 
A) 9.45 s 
B) 0.106 s 
C) 4.10 s 
D) 1.52 s 
E) 0.244 s

Question 14

The rate law for the following mechanism is Cl2(g) → 2Cl(g)
K1,fast
Cl(g)+ CO(g)   COCl(g)
K2,fast
COCl(g)+ Cl2(g)$\rightarrow$COCl2(g)+ Cl(g)
K3,slow

Accepted Answer

A) rate = k3K10.5K2[CO][Cl2]1.5.  
B) rate = k3K10.5K2[CO][Cl2]0.5.  
C) rate = k3K1K2[CO][Cl2]. 
D) rate = k3[COCl][Cl2]. 
E) rate = k3[COCl][Cl2]1.5.  
A) rate = k3K10.5K2[CO][Cl2]1.5.  
B) rate = k3K10.5K2[CO][Cl2]0.5.  
C) rate = k3K1K2[CO][Cl2]. 
D) rate = k3[COCl][Cl2]. 
E) rate = k3[COCl][Cl2]1.5.

Question 15

The reaction 2NO(g)+ O2(g)$\rightarrow$2NO2(g)has $\Delta$HrS1U1P1$\circ$S1S1P0= -114 kJ.mol-1.A possible mechanism for this reaction is 2NO(g) →N2O2(g)
Rapid equilibrium,K
N2O2(g)+ O2(g)$\rightarrow$2NO2(g)
Slow,k
If the activation energy for the reverse reaction is 225 kJ.mol-1,what is the activation energy for the forward reaction?

Accepted Answer

A) Because an intermediate is involved,the forward activation energy cannot be calculated with the given information. 
B) 111 kJ.mol-1 
C) 339 kJ.mol-1 
D) 114 kJ.mol-1 
E) 55.5 kJ.mol-1 
A) Because an intermediate is involved,the forward activation energy cannot be calculated with the given information. 
B) 111 kJ.mol-1 
C) 339 kJ.mol-1 
D) 114 kJ.mol-1 
E) 55.5 kJ.mol-1

Question 16

The reaction 2NO2(g)$\rightarrow$2NO(g)+ O2(g)
Is postulated to occur via the mechanism
NO2(g)+ NO2(g)$\rightarrow$NO(g)+ NO3(g)
Slow
NO3(g)$\rightarrow$ NO(g)+ O2(g)
Fast
An intermediate in this reaction is

Accepted Answer

A) NO2(g). 
B) ON-NO3(g). 
C) O2(g). 
D) NO(g). 
E) NO3(g). 
A) NO2(g). 
B) ON-NO3(g). 
C) O2(g). 
D) NO(g). 
E) NO3(g).

Question 17

The reaction between nitrogen dioxide and carbon monoxide is thought to occur by the mechanism 2NO2(g)$\rightarrow$ NO3(g)+ NO(g)
K1,slow
NO3(g)+ CO(g)$\rightarrow$NO2(g)+ CO2(g)
K2,fast
The rate law for this mechanism is

Accepted Answer

A) rate = k1k2[NO2]2[CO]. 
B) rate = (k1/k2)[NO2]2[CO]. 
C) rate = k1[NO3][NO]. 
D) rate = k2[NO3][CO]. 
E) rate = k1[NO2]2.  
A) rate = k1k2[NO2]2[CO]. 
B) rate = (k1/k2)[NO2]2[CO]. 
C) rate = k1[NO3][NO]. 
D) rate = k2[NO3][CO]. 
E) rate = k1[NO2]2.

Question 18

The reaction [(CN)5CoOH2]2-(aq)+ SCN-(aq)$\rightarrow$ [(CN)5CoSCN]3- + H2O(l)has the rate law,rate = k[(CN)5CoOH22-].Postulate a mechanism for this reaction.

Accepted Answer

[(CN)₅CoOH₂]²

Question 19

Consider the reaction 2N2O5(g)$\rightarrow$   4NO2(g)+ O2(g)
Rate = k[N2O5]
If the initial concentration of N2O5 is 0.80 M,the concentration after 5 half-lives is

Accepted Answer

A) 0.11 M. 
B) 0.025 M. 
C) 0.032 M. 
D) 0.16 M. 
E) 0.050 M. 
A) 0.11 M. 
B) 0.025 M. 
C) 0.032 M. 
D) 0.16 M. 
E) 0.050 M.

Question 20

Consider the reaction
A + B$\rightarrow$C + D rate = k[A]2
The time it takes for [A] to decrease from 1.0 to 0.50 M is the same as the time it takes for [A] to decrease from0.50 to 0.25 M.

Accepted Answer

A) True 
 B)False

What is the half-life of a second order reaction?

The HBr synthesis is thought to involve the following reactions: The chain termination reactions in this mechanism are reactions

If the rate of reaction increases by a factor of 9.6 when the concentration of reactant increases by a factor of 3.1,the order of the reaction with respect to this reactant is

For the elementary reaction A + 2B $\rightarrow$ products,rate = k[A][B].

For the reaction cyclopropane $\rightarrow$ propene A plot of ln[cyclopropane] vs time in seconds gives a straight line with slope -4.1 * 10^-3 s^-1 at 550^$\circ$C.What is the rate constant for this reaction?

If the average rate of decomposition of PH₃(g)is 3.2 (mol PH₃).L^-1.min^-1 for the reaction 2PH₃(g) $\rightarrow$ 2P(g)+ 3H₂(g),the unique average reaction rate is

An elementary process has an activation energy of 92 kJ/mol.If the enthalpy change for the reaction is -62 kJ/mol,what is the activation energy for the reverse reaction?

For a given first-order reaction,after 2.00 min,20% of the reactants remain.Calculate the rate constant for the reaction.

The concentration-time curves for two sets of reactions,A/B and C/D,are: Which set of reactions has the largest rate constant?

Consider the dimerization reaction below: 2A $\rightarrow$ A₂ Rate = k[A]² When the initial concentration of A is 2.0 M,it requires 30 min for 60% of A to react.Calculate the rate constant.

A first-order reaction has a half-life of 1.10 s.If the initial concentration of reactant is 0.384 M,how long will it take for the reactant concentration to reach 0.00100 M?

The reaction 2NO₂(g) $\rightarrow$ 2NO(g)+ O₂(g) Is postulated to occur via the mechanism NO₂(g)+ NO₂(g) $\rightarrow$ NO(g)+ NO₃(g) Slow NO₃(g) $\rightarrow$ NO(g)+ O₂(g) Fast An intermediate in this reaction is

The reaction between nitrogen dioxide and carbon monoxide is thought to occur by the mechanism 2NO₂(g) $\rightarrow$ NO₃(g)+ NO(g) K₁,slow NO₃(g)+ CO(g) $\rightarrow$ NO₂(g)+ CO₂(g) K₂,fast The rate law for this mechanism is

The reaction [(CN)₅CoOH₂]^2-(aq)+ SCN^-(aq) $\rightarrow$ [(CN)₅CoSCN]^3- + H₂O(l)has the rate law,rate = k[(CN)₅CoOH₂2-].Postulate a mechanism for this reaction.

Consider the reaction 2N₂O₅(g) $\rightarrow$ 4NO₂(g)+ O₂(g) Rate = k[N₂O₅] If the initial concentration of N₂O₅ is 0.80 M,the concentration after 5 half-lives is

Consider the reaction A + B $\rightarrow$ C + D rate = k[A]² The time it takes for [A] to decrease from 1.0 to 0.50 M is the same as the time it takes for [A] to decrease from0.50 to 0.25 M.

The Quantum World

Quantum Mechanics in Action: Atoms

Chemical Bonds

Molecular Shape and Structure

The Properties of Gases

Liquids and Solids

Inorganic Materials

Thermodynamics: The First Law

Thermodynamics: The Second and Third Laws

Physical Equilibria

Chemical Equilibria

Acids and Bases

Aqueous Equilibria

Electrochemistry

The Elements: the Main Group Elements

The Elements: The D Block

Nuclear Chemistry

Organic Chemistry I

Organic Chemistry II

Filters

Exam 15: Chemical Kinetics

What is the half-life of a second order reaction?

The HBr synthesis is thought to involve the following reactions: The chain termination reactions in this mechanism are reactions

For the reaction 2NO(g)+ 2H2(g) →\rightarrow→ N2(g)+ 2H2O(g) the following data were collected. What is the rate law for this reaction?

If the rate of reaction increases by a factor of 9.6 when the concentration of reactant increases by a factor of 3.1,the order of the reaction with respect to this reactant is

For the elementary reaction A + 2B →\rightarrow→ products,rate = k[A][B].

For the reaction cyclopropane →\rightarrow→ propene A plot of ln[cyclopropane] vs time in seconds gives a straight line with slope -4.1 * 10-3 s-1 at 550 ∘\circ∘ C.What is the rate constant for this reaction?

If the average rate of decomposition of PH3(g)is 3.2 (mol PH3).L-1.min-1 for the reaction 2PH3(g) →\rightarrow→ 2P(g)+ 3H2(g),the unique average reaction rate is

An elementary process has an activation energy of 92 kJ/mol.If the enthalpy change for the reaction is -62 kJ/mol,what is the activation energy for the reverse reaction?

For a given first-order reaction,after 2.00 min,20% of the reactants remain.Calculate the rate constant for the reaction.

The concentration-time curves for two sets of reactions,A/B and C/D,are: Which set of reactions has the largest rate constant?

Consider the dimerization reaction below: 2A →\rightarrow→ A2 Rate = k[A]2 When the initial concentration of A is 2.0 M,it requires 30 min for 60% of A to react.Calculate the rate constant.

A first-order reaction has a half-life of 1.10 s.If the initial concentration of reactant is 0.384 M,how long will it take for the reactant concentration to reach 0.00100 M?

The rate law for the following mechanism is Cl2(g) → 2Cl(g) K1,fast Cl(g)+ CO(g) COCl(g) K2,fast COCl(g)+ Cl2(g) →\rightarrow→ COCl2(g)+ Cl(g) K3,slow

The reaction 2NO2(g) →\rightarrow→ 2NO(g)+ O2(g) Is postulated to occur via the mechanism NO2(g)+ NO2(g) →\rightarrow→ NO(g)+ NO3(g) Slow NO3(g) →\rightarrow→ NO(g)+ O2(g) Fast An intermediate in this reaction is

The reaction between nitrogen dioxide and carbon monoxide is thought to occur by the mechanism 2NO2(g) →\rightarrow→ NO3(g)+ NO(g) K1,slow NO3(g)+ CO(g) →\rightarrow→ NO2(g)+ CO2(g) K2,fast The rate law for this mechanism is

The reaction [(CN)5CoOH2]2-(aq)+ SCN-(aq) →\rightarrow→ [(CN)5CoSCN]3- + H2O(l)has the rate law,rate = k[(CN)5CoOH22-].Postulate a mechanism for this reaction.

Consider the reaction 2N2O5(g) →\rightarrow→ 4NO2(g)+ O2(g) Rate = k[N2O5] If the initial concentration of N2O5 is 0.80 M,the concentration after 5 half-lives is

Consider the reaction A + B →\rightarrow→ C + D rate = k[A]2 The time it takes for [A] to decrease from 1.0 to 0.50 M is the same as the time it takes for [A] to decrease from0.50 to 0.25 M.

The Quantum World

Quantum Mechanics in Action: Atoms

Chemical Bonds

Molecular Shape and Structure

The Properties of Gases

Liquids and Solids

Inorganic Materials

Thermodynamics: The First Law

Thermodynamics: The Second and Third Laws

Physical Equilibria

Chemical Equilibria

Acids and Bases

Aqueous Equilibria

Electrochemistry

The Elements: the Main Group Elements

The Elements: The D Block

Nuclear Chemistry

Organic Chemistry I

Organic Chemistry II

Filters

For the elementary reaction A + 2B $\rightarrow$ products,rate = k[A][B].

For the reaction cyclopropane $\rightarrow$ propene A plot of ln[cyclopropane] vs time in seconds gives a straight line with slope -4.1 * 10^-3 s^-1 at 550^$\circ$C.What is the rate constant for this reaction?

If the average rate of decomposition of PH₃(g)is 3.2 (mol PH₃).L^-1.min^-1 for the reaction 2PH₃(g) $\rightarrow$ 2P(g)+ 3H₂(g),the unique average reaction rate is

Consider the dimerization reaction below: 2A $\rightarrow$ A₂ Rate = k[A]² When the initial concentration of A is 2.0 M,it requires 30 min for 60% of A to react.Calculate the rate constant.

The reaction 2NO₂(g) $\rightarrow$ 2NO(g)+ O₂(g) Is postulated to occur via the mechanism NO₂(g)+ NO₂(g) $\rightarrow$ NO(g)+ NO₃(g) Slow NO₃(g) $\rightarrow$ NO(g)+ O₂(g) Fast An intermediate in this reaction is

The reaction between nitrogen dioxide and carbon monoxide is thought to occur by the mechanism 2NO₂(g) $\rightarrow$ NO₃(g)+ NO(g) K₁,slow NO₃(g)+ CO(g) $\rightarrow$ NO₂(g)+ CO₂(g) K₂,fast The rate law for this mechanism is

The reaction [(CN)₅CoOH₂]^2-(aq)+ SCN^-(aq) $\rightarrow$ [(CN)₅CoSCN]^3- + H₂O(l)has the rate law,rate = k[(CN)₅CoOH₂2-].Postulate a mechanism for this reaction.

Consider the reaction 2N₂O₅(g) $\rightarrow$ 4NO₂(g)+ O₂(g) Rate = k[N₂O₅] If the initial concentration of N₂O₅ is 0.80 M,the concentration after 5 half-lives is

Consider the reaction A + B $\rightarrow$ C + D rate = k[A]² The time it takes for [A] to decrease from 1.0 to 0.50 M is the same as the time it takes for [A] to decrease from0.50 to 0.25 M.