AP Chemistry
Chapter 14 Jeopardy
Jennie L. Borders
Round 1 – Chapter 14
Rate Laws
Half-Life
Graphing
Mechanisms
Activation
Energy
Surprise
100
100
100
100
100
100
200
200
200
200
200
200
300
300
300
300
300
300
400
400
400
400
400
400
500
500
500
500
500
500
Rate Laws 100
The reaction 2ClO2 + 2OH- 
ClO3- + ClO2- + H2O was studied
with the following results:
Experiment
[ClO2] (M)
[OH-] (M)
Rate (M/s)
1
0.060
0.030
0.0248
2
0.020
0.030
0.00276
3
0.020
0.090
0.00828
Determine the rate law for the
reaction.
Rate = k[ClO2]2[OH-]
Rate Laws 200
The reaction 2ClO2 + 2OH- 
ClO3- + ClO2- + H2O was studied
with the following results:
Experiment
[ClO2] (M)
[OH-] (M)
Rate (M/s)
1
0.060
0.030
0.0248
2
0.020
0.030
0.00276
3
0.020
0.090
0.00828
Calculate the rate constant.
229.63 M-2s-1
Rate Laws 300
The reaction 2ClO2 + 2OH- 
ClO3- + ClO2- + H2O was studied
with the following results:
Experiment
[ClO2] (M)
[OH-] (M)
Rate (M/s)
1
0.060
0.030
0.0248
2
0.020
0.030
0.00276
3
0.020
0.090
0.00828
Calculate the rate when [ClO2] =
0.1M and [OH-] = 0.05M.
0.115 M/s
Rate Laws 400
The following data was measured for the
reaction BF3 + NH3  F3BNH3
Experiment
[BF3] (M)
[NH3] (M)
Initial Rate
(M/s)
1
0.250
0.250
0.2130
2
0.250
0.125
0.1065
3
0.200
0.100
0.0682
4
0.350
0.100
0.1193
5
0.175
0.100
0.0596
What is the rate law for the reaction?
Rate = k[BF3][NH3]
Rate Laws 500
The following data was measured for the
reaction BF3 + NH3  F3BNH3
Experiment
[BF3] (M)
[NH3] (M)
1
2
3
4
5
0.250
0.250
0.200
0.350
0.175
0.250
0.125
0.100
0.100
0.100
Initial Rate
(M/s)
0.2130
0.1065
0.0682
0.1193
0.0596
What is the rate when [BF3] = 0.100M and
[NH3] = 0.500M?
0.1704 M/s
Half-Life 100
How do the half-lives of first-order and
second-order reactions differ?
Since the half-lives of first-order
reactions are not based on initial
concentration, then all the half-lives
are equal. Since the half-lives of
second-order reactions are based on
initial concentrations, then each halflife is longer than the previous one.
Half-Life 200
The gas-phase decomposition of
SO2Cl2, SO2Cl2  SO2 + Cl2, is
first order in SO2Cl2. At 320oC the
rate constant is 2.2 x 10-5 s-1.
What is the half-life at this
temperature?
31,500s
Half-Life 300
Molecular iodine, I2(g), dissociates into
iodine atoms at 625K with a firstorder rate constant of 0.271 s-1.
What is the half-life of the reaction?
2.56s
Half-Life 400
Molecular iodine, I2(g), dissociates
into iodine atoms at 625K with a
first-order rate constant of 0.271s-1.
If you start with 0.050M I2 at this
temperature, how much will remain
after 5.12s assuming that the iodine
atoms do not recombine to form I2?
0.012M
Half-Life 500
The first-order rate constant for the
decomposition of N2O5, 2N2O5
 4NO2 + O2, at 70oC is 6.28 x
10-3 s-1. What is the half-life of
N2O5 at 70oC?
110.35s
Graphing 100
For a second-order reaction, what
quantity, when graphed versus
time, will yield a straight line?
1/[A]
Graphing 200
Consider the following data:
Time
(s)
Moles
of A
0
40
80
120
160
0.100
0.067
0.045
0.030
0.020
Determine whether the reaction is first
order or second order.
First Order
Graphing 300
The gas-phase decomposition of NO2,
2NO2  2NO + O2 is studied at
383oC, given the following data:
Time
(s)
[NO2]
(M)
0.0
5.0
10.0
15.0
20.0
0.100
0.017
0.009
0.0062
0.0047
Is the reaction first order or second order
with respect to the concentration of
NO2?
Second Order
Graphing 400
At 23oC and in 0.5M HCl, the following
data was obtained for the
disappearance of sucrose:
Time
0
(min)
[C12H22O11
0.316
] (M)
39
80
140
210
0.274
0.238
0.190
0.146
Is the reaction first order or second order
with respect to [C12H22O11]?
First Order
Graphing 500
Is the following reaction first or
second order?
Second Order
Mechanisms 100
The decomposition of hydrogen peroxide is
catalyzed by iodide ion. The catalyzed
reaction is thought to proceed by a twostep mechanism:
H2O2 + I-  H2O + IO- (slow)
IO- + H2O2  H2O + O2 + I- (fast)
Write the chemical equation for the overall
process.
2H2O2  2H2O + O2
Mechanisms 200
The decomposition of hydrogen peroxide is
catalyzed by iodide ion. The catalyzed
reaction is thought to proceed by a twostep mechanism:
H2O2 + I-  H2O + IO- (slow)
IO- + H2O2  H2O + O2 + I- (fast)
Predict the rate law for the overall process.
Rate = k[H2O2]
Mechanisms 300
You find the reaction 4HBr + O2  2H2O + 2Br2
to be first order with respect to HBr and first
order with respect to O2. You propose the
following mechanism:
HBr + O2  HOOBr
HOOBr + HBr  2HOBr
HOBr + HBr  H2O + Br2
Based of the rate law which step is rate
determining?
Rate = k[HBr][O2]
The first step is rate determining.
Mechanisms 400
The following mechanism has been
proposed for the reaction of NO with H2 to
form N2O and H2O:
NO + NO  N2O2
N2O2 +H2  N2O + H2O
The observed rate law is rate = k[NO]2[H2].
What can we conclude about the relative
speeds of the first and second reactions?
The second step is slow (rate
determining) and the first step is fast.
Mechanisms 500
Ozone in the upper atmosphere can be
destroyed by the following two-step
mechanism:
Cl + O3  ClO + O2
ClO + O  Cl + O2
What is the overall reaction and list any
catalysts or intermediates?
O3 + O  2O2
Catalyst – Cl
Intermediate - ClO
Activation Energy 100
What is the activation energy?
The difference in energy between
the energy to the transition state
and the energy of the reactants.
Activation Energy 200
The rate of the reaction
CH3COOC2H5 + OH-  CH3COO- + C2H5OH
Was measured at several temperatures, and the
following data was collected:
Temperature (oC)
k(M-1s-1)
15
0.0521
25
0.101
35
0.184
45
0.332
Determine this data, determine Ea.
47,041.61 J/mol
Activation Energy 300
The temperature dependence of the rate
constant for the reaction is tabulated as
follows:
Temperature (K)
k (M-1s-1)
600
0.028
650
0.22
700
1.3
750
6.0
800
23
Calculate Ea.
133,803.44 J/mol
Activation Energy 400
What part of the energy profile of a
reaction is affected by a catalyst?
Activation energy
Activation Energy 500
The oxidation of SO2 to SO3 is catalyzed by
NO2. The reaction proceeds as follows:
NO2 + SO2  NO + SO3
2NO + O2  2NO2
Why do we consider NO2 a catalyst and not an
intermediate in this reaction?
NO2 is present at the beginning and
end of the reaction. Intermediates
are formed during the reaction and
used during the reaction.
Surprise 100
What are the 4 factors that affect the
rate of a reaction?
1.Concentration of reactants
2. Catalysts
3. State of reactants
4. Temperature
Surprise 200
The decomposition of N2O5 in carbon
tetrachloride proceeds as follows:
2N2O5  4NO2 + O2. The rate law is
first order in N2O5. At 64oC the rate
constant is 4.82 x 10-3s-1. What
happens to the rate when the
concentration of N2O5 is doubled?
The rate doubles.
Surprise 300
Consider the hypothetical reaction
between A, B, and C that is first
order in A, zero order in B, and
second order in C.
How does the rate change when [A]
is doubled and the other reactant
concentrations are held constant?
The rate doubles.
Surprise 400
Consider the hypothetical reaction
between A, B, and C that is first
order in A, zero order in B, and
second order in C.
How does the rate change when [B]
is tripled and the other reactant
concentrations are held constant?
The rate remains the same.
Surprise 500
Consider the hypothetical reaction
between A, B, and C that is first
order in A, zero order in B, and
second order in C.
By what factor does the rate change
when the concentrations of all
three reactants are tripled?
The rate increases 27 fold.