Chapter 17:
Reaction Rates
Practice Test
1.
What is the instantaneous rate for a reaction that is second order in A and first order in B when [A] = 2
M
and [B] = 3
M
? The specific rate constant for the reaction is 0.1
M
-2
s
-1
.
a.
1.2
M/s
b.
0.012
M/s
c.
0.12
M/s
d.
12
M/s
Hint
2.
The term that describes the change in the concentration of a reactant divided by the change in time of the reaction is the ____________.
a.
rate constant
b.
average reaction rate
c.
chemical reaction
d.
activated complex
Hint
3.
What Greek symbol is used to represent change?
a.
b.
c.
→
d.
Δ
Hint
4.
In the rate-law expression, Rate =
k
[A], what does the symbol
k
represent?
a.
instantaneous rate
b.
reaction order
c.
concentration
d.
specific rate constant
Hint
5.
What is the slowest of the elementary steps in a complex reaction called?
a.
mechanism
b.
fast step
c.
propagating step
d.
rate-limiting step
Hint
6.
Automobiles use a catalytic converter made of metal to ensure complete combustion of gasoline. What type of catalyst is present in automobiles?
a.
homogeneous catalyst
b.
solid-state catalyst
c.
heterogeneous catalyst
d.
ephemeral catalyst
Hint
7.
When you increase the temperature of a chemical reaction, the ____________.
a.
reaction rate does not change
b.
reaction stops
c.
reaction speeds up
d.
reaction slows down
Hint
8.
What are the individual steps in a complex reaction known as?
a.
intermediate steps
b.
complex steps
c.
elementary steps
d.
rate-determining steps
Hint
9.
What is the term given to a temporary arrangement of atoms that may produce either products or reactants?
a.
reactant
b.
activation energy
c.
collision
d.
transition state
Hint
10.
What is the name given to a catalyst that exists in the same physical state as the reaction being catalyzed?
a.
solid-state catalyst
b.
homogeneous catalyst
c.
ephemeral catalyst
d.
heterogeneous catalyst
Hint
11.
How much time has passed when 5 mol/L have reacted at an average rate of 0.5 mol/L·s?
a.
100 s
b.
0.1 s
c.
10 s
d.
1.0 s
Hint
12.
The exponents in a rate-law expression define the __________, which describes how the rate is affected by the concentration of the reactant.
a.
instantaneous rate
b.
concentration
c.
specific rate constant
d.
reaction order
Hint
13.
What are the units that generally express a reaction rate?
a.
liters per mole per second
b.
seconds per liter per mole
c.
moles per liter per second
d.
seconds per mole per liter
Hint
14.
What happens to the activation energy of the reaction when a catalyst is present?
a.
The activation energy decreases.
b.
The activation energy increases.
c.
The activation energy does not change.
d.
The reaction stops.
Hint
15.
A substance that speeds up the reaction rate but is not consumed in the reaction is a(n) ____________.
a.
inhibitor
b.
product
c.
catalyst
d.
reactant
Hint
16.
What is the most common experimental method for evaluating a reaction order called?
a.
method of final rates
b.
method of instantaneous rates
c.
method of experimental rates
d.
method of initial rates
Hint
17.
Which of the following is the theory that states that atoms, molecules, and ions must collide for a chemical reaction to occur?
a.
mechanism
b.
accident theory
c.
collision theory
d.
reaction theory
Hint
18.
When the concentration of a reactant is increased, the _______________.
a.
reaction speeds up
b.
reaction rate does not change
c.
reaction slows down
d.
reaction stops
Hint
19.
What will happen when you decrease the surface area of a reactant?
a.
The reaction speeds up.
b.
The reaction slows down.
c.
The reaction stops.
d.
The reaction rate does not change.
Hint
20.
What is the overall reaction order for the following rate-law expression? Rate =
k
[A][B]
2
[C]
3
a.
6
b.
5
c.
4
d.
7
Hint
