Download CH 14-15 Chapter 14-15 review wkey

Hazen  AP Chemistry
Name _______________________________
Period ___ Date ___/___/___
14  Chemical Kinetics
R e v i e w
1.
Which of the following does NOT influence the speed of a chemical reaction?
a) concentration of reactants
b) nature of reactants
c) temperature
d) presence of a catalyst
e) none of these
2.
What would cause the change in the kinetic energy diagrams as shown?

KE
a)
b)
c)
d)
e)
3.
increasing the H
decreasing the temperature
increasing the surface area
addition of a catalyst
increasing the concentration of reactant
A time vs. concentration graph is presented below for the reaction A  B. What is the rate of
appearance of ‘B’ 20 seconds after the start of the reaction?
a) 0.050 mol/Ls
b) 3.2 mol/Ls
4.
KE
d) 0.010 mol/Ls
e) 9.8 mol/Ls
c) 2.2 mol/Ls
The reaction 3O2  2O3 is proceeding with a rate of disappearance of O2 equal to 0.60 mol/Ls. What
is the rate of appearance of O3, in mol/Ls?
a) 0.60
b) 0.40
d) 0.90
e) 1.20
c) 0.10
5.
A reaction has the rate law Rate = k[A]2[B]. What is the overall order of the reaction?
a) 0
b) 2
c) 1
d) 4
e) 3
6.
What are the correct units for a second order rate constant?
a) mol/Ls
d) L2/mol2s
b) 1/s
e) mol2/L2s
c) L/mols
7.
The reaction I- + OCl-  IO- + Cl- is first order with respect to I- and first order with respect to OCl-.
The rate constant is 6.1 x 10-2 L/mols. What is the rate of reaction when [I-] = 0.10 M and [OCl-] =
0.20 M?
a) 2.4 x 10-4 M/s
b) 1.2 x 10-3 M/s
c) 6.1 x 10-3 M/s
8.
9.
d) 1.2 x 10-4 M/s
e) 2.4 x 10-5 M/s
A reaction and its rate law are given below. When [C4H6] = 2.0 M, the rate is 0.106 M/s.
What is the rate when [C4H6] = 4.0 M?
2 C4H6  C8H12
Rate = k[C4H6]2
a) 0.053 M/s
d) 0.424 M/s
b) 0.212 M/s
c) 0.106 M/s
e) 0.022 M/s
The rate law for the reaction
is Rate
= k[NO]2[O2].
2NO(g) + O2(g)  2NO2(g)
What happens to the rate when the concentration of NO is doubled?
a) the rate doubles d) the rate is halved
b) the rate triples
e) none of these
c) the rate quadruples
10. Below is some rate data for the hypothetical reaction, 2A + B  C. What is the rate law for this
reaction?
Experiment
1
2
3
a) Rate = k[A][B] d) Rate = k[A]2[B]2
b) Rate = k[A]2[B] e) Rate = k[B]2
c) Rate = k[A][B]2
[A]o
2.0 M
2.0 M
4.0 M
[B]o
1.0 M
2.0 M
1.0 M
Rate (M/s)
0.100
0.400
0.100
11. The acid catalyzed decomposition of hydrogen peroxide is a first order reaction with the rate constant
given below. For an experiment in which the starting concentration of hydrogen peroxide is 0.110 M,
what is the concentration of H2O2 450 minutes after the reaction begins?
2H2O2  2H2O + O2 k=1.33 x 10-4 min-1
a) 0.0961 M
b) 0.104 M
c) 0.117 M
d) 0.00658 M
e) 0.0156 M
12. What is the rate constant for a first order reaction for which the half-life is 85.0 sec?
a) 0.00814 sec-1
d) 0.0118 sec-1
b) 4.44 sec-1
e) 58.9 sec-1
c) 0.170 sec-1
13.What fraction of a reactant remains after 3 half-lives of a first order reaction?
a) 1/2
d) 1/8
b) 1/3
e) 1/12
c) 1/6
14. Assume a reaction occurs by the mechanism given below. What is the rate law for the reaction?
A+BC
fast
CD
slow
a) Rate = k[A][B][C]
b)
c)
d)
e)
Rate = k[A]2
Rate = k[A][B]
Rate = k[A][B]/[D]
Rate = k[A]
15. According to collision theory, which of the following factors does NOT influence the rate of reaction?
a) collision frequency
b) collision energy
c) collision orientation
d) collision rebound direction
e) none of these
16. What distance corresponds to the activation energy for the reaction of X to Y?
a) a
b) b
c) c
d) d
e) e
17. At what point on the potential energy diagram given below does the transition state (activated complex)
occur?
a) a
b) b
c) c
d) d
e) e
18. The rate constants, at two different temperatures, for the reaction
CH I + Br-  CH Br + I3
are given below.
t = 30C
t = 49C
3
k = 1.38 x 10-4 M-1s-1
k = 1.21 x 10-3 M-1s-1
What is the activation energy for this reaction? R = 8.314 J/molK.
a) 92.7 kJ/mol
d) 343 kJ/mol
b) 200 kJ/mol
e) none of these
c) 40.3 kJ/mol
19. Which of the following is NOT true about a catalyst?
a) it speeds up the forward reaction
b) is acts as an inhibitor
c) it speeds up the reverse reaction
d) it may be homogeneous
e) it may be heterogeneous
20.
In the reaction, H2 + Br2  2HBr, the step Br + H2  HBr + H is what step?
a) initiation
b) completion
c) inhibition
d) propagation
e) termination
21. In the reaction, H2 + Br2  2HBr, the step Br + Br  Br2 is what step?
a) initiation
b) completion
c) inhibition
d) propagation
e) termination
22. A free radical is a chemical species that possesses
a) a positive charge
b) a negative charge
c) an unpaired electron
d) an oxygen atom
e) unconventional political views
15  Chemical Equilibrium
R e v i e w
1.
Consider the reaction system,
CoO(s) + H2(g) Co(s) + H2O(g).
The equilibrium constant expression is
[CoO][H 2 ]
[H 2 ]
a)
d)
[Co][H 2 O]
[H 2 O]
[Co][H 2 O]
[H 2 O]
b)
e)
[CoO][H 2 ]
[H 2 ]
[Co][H 2 O]
c)
[H 2 ]
Questions 3 & 4 refer to the following:
At a given temperature, 0.300 mole NO,
0.200 mol Cl2 and 0.500 mol ClNO were
placed in a 25.0 Liter container. The
following equilibrium is established:
2ClNO(g) 2NO(g) + Cl2(g)
3.
2.
Given the equilibrium,
2SO2(g) + O2(g) 2SO3(g), if this
equilibrium is established by beginning with
equal number of moles of SO2 and O2 in a
1.0 Liter bulb, then the following must be
true at equilibrium:
a) [SO2] = [SO3]
d) [SO2] < [O2]
b) 2[SO2] = 2[SO3] e) [SO2] > [O2]
c) [SO2] = [O2]
At equilibrium, 0.600 mol of ClNO was
present. The number of moles of Cl2
present at equilibrium is
a) 0.050
d) 0.200
b) 0.100
e) 0.250
c) 0.150
4.
The equilibrium constant, Kc, is:
a) 4.45 x 10-4
b) 6.67 x 10
c) 0.111
5.
-4
8.
d) 0.167
e) 1500
present. What is Kc for this reaction?
2NO(g) N2(g) + O2(g)
a) 9.92
b) 3.15
c) 0.0372
At 985C, the equilibrium constant for the
reaction,
H2(g) + CO2(g) H2O(g) + CO(g)
is 1.63. What is the equilibrium constant for
the reverse reaction?
a) 1.63
d) 0.613
b) 0.815
c) 2.66
0.200 mol NO is placed in a one liter flask
at 2273 K. After equilibrium is attained,
0.0863 mol N2 and 0.0863 mol O2 are
9.
d) 39.7
e) 0.576
N2O4(g) 2 NO2(g)
At 25C, 0.11 mole of N2O4 reacts to form
0.10 mol of N2O4 and 0.02 mole of NO2.
At 90C, 0.11 mole of N2O4 forms 0.050
mole of N2O4 and 0.12 mole of NO2. From
e) 1.00
these data we can conclude
a) N2O4 molecules react by a second order
6.
7.
What is the relationship between Kp and Kc
for the reaction, 2ICl(g) I2(g) + Cl2(g)?
a) Kp = Kc(RT)-1
d) Kp = Kc
b) Kp = Kc(RT)
e) Kp = Kc(2RT)
c) Kp = Kc(RT)2
For the reaction 2NO2(g)
rate law.
b) N2O4 molecules react by a first order rate
law.
c) the reaction is exothermic.
d) N2O4 molecules react faster at 25C than
at 90C.
e) the equilibrium constant for the reaction
above increases with an increase in
temperature.
N2O4(g), Kp at
25C is 7.3, when all partial pressures are
expressed in atmospheres. What is Kc for
this reaction? [R=0.0821 Latmmol-1K-1]
a) 4270
d) 179
b) 0.0119
e) 2.06
c) 0.291
10. For the equilibrium system
H2O(g) + CO(g) H2(g) + CO2(g)
H = -42 kJ/mol
Kc equals 0.62 at 1260 K. If 0.10 mole each
of H2O, CO, H2 and CO2 (each at 1260 K)
a)
b)
c)
d)
e)
were placed in a 1.0-Liter flask at 1260 K,
when the system came to equilibrium…
The temperature
The mass of CO
would
would
decrease
increase
decrease
decrease
remain constant
increase
increase
decrease
increase
increase
11. For the reaction system,
N2(g) + 3H2(g) 2NH3(g) + heat
the conditions that would favor maximum
conversion of the reactants to products
would be
a) high temperature and high pressure
b) high temperature, pressure unimportant
c) high temperature and low pressure
d) low temperature and high pressure
e) low temperature and low pressure
12. Solid HgO, liquid Hg, and gaseous O2 are
placed in a glass bulb and are allowed to
reach equilibrium at a given temperature.
2HgO(s) 2Hg(l) + O2(g) H = +43.4 kcal
The mass of HgO in the bulb could be
increased by
a) adding more Hg.
b) removing some O2.
c) reducing the volume of the bulb.
d) increasing the temperature.
e) removing some Hg.