NEW
Font size
S
M
L
XL
WorksheetsKinetics: AP Chemistry
Total questions: 72
Worksheet time: 42mins
Name
Class
Date
1.
What does kinetics mainly study?
a)
concentration of (aq) mixtures
b)
pressure of (g) mixtures
c)
how much products are produced
d)
reaction rates
2.
Which factors significantly affect reaction rate?
a)
temperature
b)
presence of a catalyst
c)
amount of chemical
d)
all of the above and other factors
3.
A catalyst:
a)
appears in the reactants of an early elementary step of a proposed reaction mechanism
b)
appears in the products of the last proposed reaction mechanism
c)
can affect reaction rate, but is not used up in a chemical reaction
d)
all of the above
4.
A catalyst:
a)
cannot infinitely increase reaction rate
b)
helps reactants fit better together
c)
must both bond reactants, and eventually be released from chemicals
d)
all of the above
5.
A catalyst:
a)
increases activation energy of a chemical reaction
b)
decreases activation energy of a chemical reaction
c)
cannot be destroyed with high temperatures
d)
all of the above
6.
A catalyst:
a)
is more efficient if it is homogeneous
b)
is more efficient if its state matches that of the substrate reactants it originally bonds to
c)
is more efficient if it is heterogeneous
d)
all of the above
7.
A catalyst:
a)
should be eliminated when we solve elementary reaction steps of a proposed reaction mechanism simultaneously
b)
should always be introduced and eliminated in the first elementary step of a proposed reaction mechanism
c)
lowers the amount of energy released by an exothermic reaction
d)
lowers the amount of energy added to a reaction
8.
Increasing temperature of a chemical reaction:
a)
increases the number of collisions per second of chemical reactants
b)
increases the speed of reaction
c)
can increase the pressure of reactants
d)
all of the above
9.
Many kinetics equations fit a slope intercept form. The Arrhenius equation is k = A e−(Ea/RT). The slope of a plot of ln k vs. 1/T is equal to:
a)
-k
b)
k
c)
activation energy
d)
-Ea/ R
10.
What is the slope of an Arrhenius plot for the following reaction? 2NOCl → 2NO + Cl2
Temperature (K) k (L/mol·s) 400. 6.6 × 10−4 500. 2.9 × 10−1 600. 16.3
Temperature (K) k (L/mol·s) 400. 6.6 × 10−4 500. 2.9 × 10−1 600. 16.3
a)
8.18 × 10 to the -2 K
b)
5.06 × 10 to the -2 K
c)
−1.22 × 10 to the 4th K
d)
−1.96 × 10 to the 4th K
11.
The activation energy for the reaction
CH3CO → CH3 + CO is 71 kJ/mol. How many times greater is the rate constant for this reaction at 170°C than at 150°C?
CH3CO → CH3 + CO is 71 kJ/mol. How many times greater is the rate constant for this reaction at 170°C than at 150°C?
a)
0.40
b)
1.1
c)
2.5
d)
4.0
12.
A chemical reaction can occur:
a)
if the particles collide with enough energy
b)
if the particles collide with sufficient activation energy
c)
if the particles collide with correct orientation
d)
all of the above
13.
In a chemical reaction which goes forward:
a)
typically all reactants go forward toward the products
b)
typically some of the reactants go forward toward the products
c)
typically all reactants have just the right amount of activation energy to go forward toward the products
d)
typically all reactants have just the right orientation to go forward toward the products
14.
The mechanism of a chemical reaction is the sequence of actual events that take place as reactant molecules are converted into products.
Which of the following is true?
Which of the following is true?
a)
Each of these events constitutes an elementary step that can be represented as a coming-together of discrete particles ("collision").
b)
Each of these events constitutes an elementary step that can be represented as the breaking-up of a molecule ("dissociation") into simpler units.
c)
The molecular entity that emerges from each step may be a final product of the reaction, or it might be an intermediate.
d)
all of the above are true
15.
Consider the decomposition of nitrogen dioxide into nitric oxide and oxygen. The net balanced equation is: 2NO2(g)→2NO(g)+O2(g)
The mechanism of this reaction is believed to involve the following two elementary steps:
1st: 2NO2→NO3+NO
2nd: NO3→NO+O2
The mechanism of this reaction is believed to involve the following two elementary steps:
1st: 2NO2→NO3+NO
2nd: NO3→NO+O2
a)
NO3 has only a transient existence and does not appear in the net equation. It is an intermediate.
b)
NO3 has a permanent existence and does appear in the overall net equation.
c)
NO3 would appear at the highest point of an Time Vs. Energy Curve when graphed.
d)
NO3 is known as an activated complex or transition state.
16.
A useful reaction mechanism consists of a series of elementary steps (defined below) that:
a)
can be written as chemical equations, and whose sum gives the net balanced reaction equation.
b)
must agree with the experimental rate law.
c)
may be different under different conditions.
d)
all of the above
17.
Elementary reactions differ from ordinary net chemical reactions. Which of the following statements is false?
a)
A bimolecular process always follows the second-order rate law.
b)
Elementary steps often involve unstable or reactive species that do not appear in the net reaction equation.
c)
Net reactions may have different proposed elementary steps, and all are viable if they solve simultaneously to the overall net reaction, unless proved experimentally false.
d)
Some net reactions do proceed in a single elementary step, at least under certain conditions. The presence of a catalyst however cannot enable an alternative mechanism that greatly speeds up the rate of a reaction.
18.
Which type of elementary reaction is most common?
a)
unimolecular
b)
bimolecular
c)
termolecular
d)
none of the above, they are all equally common
19.
Multi-step (Consecutive) Reactions:
Mechanisms in which one elementary step is followed by another are very common.
step 1: A + B → Q
step 2: B + Q → C
net reaction: A + 2B → C
Which of the following is false?
Mechanisms in which one elementary step is followed by another are very common.
step 1: A + B → Q
step 2: B + Q → C
net reaction: A + 2B → C
Which of the following is false?
a)
The net reaction is just the sum of its elementary steps.
b)
The species Q is an intermediate, usually an unstable or highly reactive species.
c)
Intermediates such as Q can appear in the rate law of a net reaction.
d)
If both steps proceed at similar rates, rate law experiments on the net reaction would not reveal that two separate steps are involved here.The rate law for the reaction would berate=k[A][B]2
20.
The rate-determining step is also known as the rate-limiting step. Consider a 3 elementary step proposed mechanism.
1st step: fast
2nd step: slow
3rd step: fast
Which of the following is false?
1st step: fast
2nd step: slow
3rd step: fast
Which of the following is false?
a)
The rate law for the overall net reaction must simply include concentration(s), reaction orders, and a rate constant for that rate-determining step.
b)
We can generally expect that one of the elementary reactions in a sequence of consecutive steps will have a rate constant that is smaller than the others.
c)
The effect is to slow the rates of all the reactions.
d)
The overall rate law must include information from both the slow step and any step(s) before it.
21.
A "zeroth" order reaction for A-->B, will show:
a)
a straight line for a graph: time vs. ln [A]
b)
a straight line for a graph: time vs. [A].
c)
a straight line for a graph: time vs. 1/[A]
d)
none of the above
22.
A zeroth order rate law for reaction A--> B will match a graph:
a)
which is straight and positive in slope for time vs. [A].
b)
which is straight and negative in slope for time vs. [A].
c)
which is non-linear and positive in slope for time vs. [A].
d)
which is non-linear and positive in slope for time vs. ln[A].
23.
A first order rate law for reaction A--> B will match a graph:
a)
which looks linear and positive in slope for time vs. ln [A].
b)
which looks non-linear and positive in slope for time vs. ln [A].
c)
which looks non-linear and negative in slope for time vs. ln [A].
d)
which looks linear and negative in slope for time vs. ln [A].
24.
A 2nd order rate law for reaction A--> B will match a graph:
a)
which looks linear and positive in slope for time vs. 1/ [A].
b)
which looks linear and negative in slope for time vs. 1/ [A].
c)
which looks non-linear and positive in slope for time vs. 1/ [A].
d)
which looks non-linear and negative in slope for time vs. 1/[A].
25.
For a second order reaction, the half-life is equal to:
a)
0.693/k
b)
k/0.693
c)
1/k[A]o
d)
k
26.
For a 1st order reaction, the half-life ("t1/2") is equal to:
a)
t1/2 = 0.693/k
b)
t1/2 = k/0.693
c)
t1/2 = 1/k[A]o
d)
t1/2 = k
27.
What is true of the half-life of a chemical reaction?
a)
For a 1st order reaction, the half-life ("t1/2") is not dependent upon initial concentration.
b)
Half-life is a good estimate of reaction rate.
c)
Half-life helps us determine how long it takes for half of the starting concentration to change into product.
d)
All of the above are true
28.
Rate constants are:
a)
part of rate laws
b)
temperature dependent
c)
usually part of the slope in the slope-intercept equation form of a line
d)
all of the above
29.
Given the following data for this reaction:
NH4+(aq) + NO2-(aq) N2(g) + 2H2O(l)
on your sheet. The rate law for the reaction is:
NH4+(aq) + NO2-(aq) N2(g) + 2H2O(l)
on your sheet. The rate law for the reaction is:
a)
(a) Rate = k[NH4+][NO2-]
b)
(b) Rate = k[NH4+]2[NO2-]2
c)
(c) Rate = k[NH4+]2[NO2-]
d)
(d) Rate = k[NH4+][NO2-]2
30.
For an overall reaction order of 1, what will rate constant "k" have for its units?
a)
1/s or s -1
b)
M/s or M x s-1
c)
1/Mxs or M-1 x s-1
d)
1/M2 x s or M-2 x s-1
31.
Elements which are good catalysts and have ability to change their oxidation number or charge and their ability to bond to reactants effectively tend to be of what kind of element:
a)
Transition elements from the middle of the Periodic Table
b)
Nobel gases from group 8A
c)
Alkali metals from group 1A
d)
Any non-metal
32.
For an overall reaction order of 2, what will rate constant "k" have for its units?
a)
1/s or s-1
b)
M/s or M x s-1
c)
1/Mxs or M-1 x s-1
d)
1/M2 x s or M-2 x s-1
33.
For a first order reaction: A--> B
the slope intercept for of the equation y=mx + b can help us study the reaction rate.
Which of the following is true?
the slope intercept for of the equation y=mx + b can help us study the reaction rate.
Which of the following is true?
a)
Natural log of the initial concentration =y
b)
Natural log of the final concentration is = to the y intercept "b"
c)
-k is the slope or "m"
d)
Concentration is equal to x.
34.
If temperature in increased,
a)
k is higher
b)
activation energy is lowered
c)
the speed of reaction goes up
d)
all of the above
35.
If we have two gases combining in a reaction to give a new product C: A + B --> C, how can we speed up the reaction?
a)
increase pressure of A
b)
decrease pressure of A
c)
cool A until it is a liquid
d)
none of the above
36.
How do you calculate the overall reaction order of a chemical reaction?
a)
add up the coefficients of the slow step of a reaction mechanism
b)
take the largest concentration reactant's coefficient
c)
add up all coefficients of all slow and fast steps in a proposed reaction mechanism
d)
add up the reaction orders of all elementary steps including only the slow step and any earlier steps
37.
Which one of the following changes would alter the rate constant (k) for a chemical reaction?
a)
A. increasing the concentration of A
b)
B. increasing the concentration of B
c)
C. increasing the temperature
d)
D. measuring k again after the reaction has run for a while
38.
Consider the reaction: P4 + 6 H2 → 4 PH3. A rate study of this reaction was conducted at 298 K. The data that were obtained are shown in the table on your paper. What is the reaction order with for P4?
a)
zero
b)
1st
c)
2nd
d)
none of the above
39.
Consider the reaction: P4 + 6 H2 → 4 PH3. A rate study of this reaction was conducted at 298 K. The data that were obtained are shown in the table on your paper. What is the reaction order with for H2?
a)
0
b)
1st
c)
2nd
d)
none of the above
40.
The rate law for a reaction is rate = k [A][B]2 Which one of the following statements is false?
a)
A) If [B] is doubled, the reaction rate will increase by a factor of 4.
b)
B) The reaction is second order in B.
c)
C) The reaction is first order in A.
d)
D) The reaction is second order overall.
41.
If the concentration of a reactant has zeroth order, it means:
a)
the multiple of the concentration change affects the reaction rate by the same multiple
b)
the multiple of the concentration change affects the reaction rate by a multiple of 2
c)
the multiple of the concentration change affects the reaction rate by a multiple of 4
d)
there is no effect of the concentration change on the reaction rate
42.
The rate of a reaction depends on __________.
a)
A) collision frequency
b)
B) collision orientation
c)
C) collision energy
d)
D) all of the above
43.
Activation energy when graphed can be calculated by:
a)
finding the difference in energy between the reactants and the transition state
b)
finding the energy between the transition state and the products
c)
finding the difference in energy between the reactants and products
d)
none of the above
44.
In an energy profile of: Time Vs. Energy, where are the intermediates found?
a)
at the far left start of the curve
b)
at the top of the hill of the curve(s)
c)
at the bottom of the valleys of the curve(s)
d)
none of the above
45.
The mechanism for formation of the product X is:
A + B -> C + D (slow)
B + D -> X (fast)
The intermediate reactant in the reaction is ___.
A + B -> C + D (slow)
B + D -> X (fast)
The intermediate reactant in the reaction is ___.
a)
A
b)
B
c)
C
d)
D
46.
For the elementary reaction NO3 + CO -> NO2 + CO2 the molecularity of the reaction is _______, and the rate law is rate = _______.
a)
A) 4, k[NO3][CO][NO2][CO2]
b)
B) 2, k[NO3][CO]
c)
C) 4, k[NO2][CO2]/[NO3][CO]
d)
D) 2, k[NO2][CO2]
47.
Generally speaking, graphs of reaction rates for 1st order reactions, are steeper when:
a)
k is higher
b)
T is higher
c)
the slope of the curve is higher
d)
all of the above
48.
How do we find the instantaneous reaction rate?
a)
take two plots on the rate curve and find the slope
b)
find a point on the curve and estimate the slope
c)
draw a tangent line to the reaction rate curve and find the slope
d)
none of the above
49.
The rate law of the overall reaction A + B--> C is rate = k[A]2. Which of the following will not increase the rate of the reaction?
a)
A) increasing the concentration of reactant A
b)
B) increasing the temperature of the reaction
c)
C) increasing the concentration of reactant B
d)
D) adding a catalyst for the reaction
50.
A reaction's rate:
a)
starts faster then slows down
b)
stays constant
c)
starts slower then speeds up
d)
none of the above
51.
A fluctuating 3 hill curve energy profile will be provided. Which is the fastest forward reaction?
a)
A
b)
B
c)
C
d)
More than one of the curves has the fastest forward rate.
52.
A fluctuating 3 hill curve energy profile will be provided. Which is the fastest reverse reaction?
a)
A
b)
B
c)
C
d)
More than one of the above has the fastest rate.
53.
Bimolecular means:
a)
2 molecules react
b)
3 molecules react
c)
1 molecule reacts
d)
none of the above
54.
Suppose the reaction: A + 2B AB2 occurs by the following mechanism:
Step 1: A + B--> AB slow
Step 2: AB + B -->AB2 fast
Overall: A + 2B AB2
The rate law expression must be Rate =______.
Step 1: A + B--> AB slow
Step 2: AB + B -->AB2 fast
Overall: A + 2B AB2
The rate law expression must be Rate =______.
a)
(a) k[A]
b)
(b) k[B]
c)
(c) k[A][B]
d)
(d) k[B]2
55.
Consider the following mechanism.
Step 1: O3 → O2 + O (fast)
Step 2: O3 + O → 2 O2 (slow)
What is the overall balanced equation?
Step 1: O3 → O2 + O (fast)
Step 2: O3 + O → 2 O2 (slow)
What is the overall balanced equation?
a)
4 O3 → 3 O2
b)
O3 → 3 O2
c)
3 O3 → 2 O2
d)
2 O3 → 3 O2
56.
Consider the following mechanism.
Step 1: O3 → O2 + O (fast)
Step 2: O3 + O → 2 O2 (slow)
What is the order with respect to each reactant?
Step 1: O3 → O2 + O (fast)
Step 2: O3 + O → 2 O2 (slow)
What is the order with respect to each reactant?
a)
1st
b)
2nd
c)
3rd
d)
0
57.
If the reaction: 2HI-->2H2 + I2 HI is first order, which of the following will yield a linear plot?
a)
a. log [HI] vs time
b)
b. 1/[HI] vs time
c)
c. [HI] vs time
d)
d. ln [HI] vs time
58.
Consider the rate law: rate = k[Y]m[Z]n.
How are the exponents m and n determined?
How are the exponents m and n determined?
a)
by using subscripts of the chemical
b)
by using the coefficients of the balanced chemical formulas
c)
by hypothesis
d)
by experiment
59.
At 300 K, the following reaction is found to obey the rate law: Rate = k[NOCl]2
2NOCl 2NO + Cl2
Consider the three postulated mechanisms given below. Then choose the response that lists all those that are possibly correct and no others.
Mechanism 1:
NOCl --> NO + Cl slow
Cl + NOCl --> NOCl2 fast
NOCl2 + NO --> 2NO + Cl2 fast
Overall: 2NOCl --> 2NO + Cl2
Mechanism 2:
2NOCl --> NOCl2 + NO slow
NOCl2 -->NO + Cl2 fast
Overall: 2NOCl --> 2NO + Cl2
Mechanism 3:
NOCl --> NO + Cl fast, equilibrium
NOCl + Cl --> NO + Cl2 slow
Overall: 2NOCl --> 2NO + Cl2
2NOCl 2NO + Cl2
Consider the three postulated mechanisms given below. Then choose the response that lists all those that are possibly correct and no others.
Mechanism 1:
NOCl --> NO + Cl slow
Cl + NOCl --> NOCl2 fast
NOCl2 + NO --> 2NO + Cl2 fast
Overall: 2NOCl --> 2NO + Cl2
Mechanism 2:
2NOCl --> NOCl2 + NO slow
NOCl2 -->NO + Cl2 fast
Overall: 2NOCl --> 2NO + Cl2
Mechanism 3:
NOCl --> NO + Cl fast, equilibrium
NOCl + Cl --> NO + Cl2 slow
Overall: 2NOCl --> 2NO + Cl2
a)
2, 3
b)
3
c)
1
d)
2
60.
When a chemical change (chemical reaction) is at equilibrium, what does that say about its forward and reverse reaction rates?
a)
they are equal
b)
no conclusions are made about reaction rate
c)
forward rate always is faster
d)
reverse rate is always faster
61.
If the vertical axis is labelled by the natural log of a reactant concentration, then we are speaking of what reaction order?
a)
0
b)
1st
c)
2nd
d)
none of the above
62.
If the vertical axis is labelled by the inverse of a reactant concentration, then we are speaking of what reaction order?
a)
0
b)
1st
c)
2nd
d)
none of the above
63.
Intermolecular forces can interfere with the speed of a reaction.
a)
true
b)
false
64.
Factors affecting speed of reaction include:
a)
a. boiling point
b)
b. change is mass
c)
c. pressure
65.
Most reactions are more rapid at high temperatures than at low temperatures. This is consistent with:
(I) an increase in the activation energy with increasing temperature.
(II) an increase in the rate constant with increasing temperatures.
(III) an increase in the percent of "high energy" collisions with increasing temperature.
(I) an increase in the activation energy with increasing temperature.
(II) an increase in the rate constant with increasing temperatures.
(III) an increase in the percent of "high energy" collisions with increasing temperature.
a)
only I
b)
only II
c)
only I and II
d)
only II and III
66.
Rate of reaction can be calculated by dividing molarity or pressure by:
a)
mass
b)
volume
c)
temperature
d)
time
67.
Kinetics studies:
a)
the disappearance of reactants
b)
the appearance of products
c)
both of the other answers
68.
In a 2nd order reaction slope intercept equation form, what is the slope?
a)
initial concentration
b)
final concentration
c)
k
d)
-k
69.
Which statement is false?
a)
(a) If a reaction is thermodynamically spontaneous, it must have a low activation energy
b)
(b) If a reaction is thermodynamically spontaneous it may occur slowly.
c)
(c) Activation energy can be overcome by increasing the frequency of reactant collision with the presence of a catalyst.
d)
(d) If a reaction is thermodynamically non-spontaneous, it will not occur spontaneously.
70.
If the activation energy in the forward direction of an elementary step is 52 kJ and the activation energy in the reverse direction is 74 kJ, we know:
a)
the forward reaction is faster
b)
the reverse reaction is faster
c)
forward and reverse reactions are equal in reaction rate
71.
The half-life for a first-order reaction is 32 s. What was the original concentration if, after 2.0 minutes, the reactant concentration is 0.062 M?
a)
a. .84 M
b)
b. .069 M
c)
c. .091 M
d)
d. .075 M
72.
If I wanted steel wool to oxidize or "burn" quicker, I could:
a)
increase the amount of oxygen
b)
limit the amount of interacting or colliding particle collision
c)
ball up the steel wool more
d)
limit the number of places I light steel wool and add activation energy
Reset
