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Unit 12 Review

Total questions: 80

Worksheet time: 2hrs 26mins

Name
Class
Date
1.

In order to burn a tree log faster, we must...

a)

Take away the oxygen

b)

Increase the surface area (chop it up)

c)

Put water on it

d)

Decrease the temperature

2.

This is a substance that increases the rate of a chemical reaction without being consumed by the reaction.

a)

A thermometer

b)

A match

c)

A catalyst

d)

A substrate

3.

When we chew our food, we are helping speed up the digestion reaction because we are...

a)

Increasing the temperature

b)

Increasing the concentration

c)

Increasing the number of particles

d)

Increasing the surface area

4.

A television news programme shows an explosion at a flour mill.

What could have increased the risk of such an explosion?

a)

adding salt to the flour

b)

employing more staff in the mill

c)

grinding the flour more finely

d)

opening the windows

5.

Activation energy is

a)

energy possessed by the reactants

b)

energy formed during the collision between reactants

c)

energy released during bond formation

d)

energy required for the reactants to change into product

6.

Which does not increase the speed of a reaction?

a)

adding a catalyst

b)

increasing the concentration of one of the reactants

c)

increasing the particle size of one of the reactants

d)

increasing the temperature

7.

The rate of a reaction depends on temperature, concentration, particle size and catalysts.

Which statement is not correct?

a)

Catalysts can be used to increase the rate of reaction.

b)

Higher concentration decreases the rate of reaction.

c)

Higher temperature increases the rate of reaction.

d)

Larger particle size decreases the rate of reaction

8.

How does a catalyst increase the speed of a reaction?

a)

by increasing the collision frequency of particles

b)

by increasing the speed of the particles

c)

by increasing the temperature of the reaction

d)

by lowering the activation energy

9.

Which of the following are true about how temperature affects the rate of reaction?

a)

I and II only

b)

I and III only

c)

II and III only

d)

I, II, and III

10.
When the rate of the forward reaction is equal to the rate of backward reaction, the system is said to be in
a)
Chemical Equilibrium
b)
Chemical Balance
c)
Stoichiometry
d)
Chemical Reaction
11.
What letter represents the activation energy?
a)
A
b)
B
c)
C
d)
D
12.

The tangent to the curve in the plot of concentration vs time allows us to calculate

a)

Instant rate at 300 s

b)

instant rate at the beginning of the reaction

c)

Average rate between 200 s and 400 s

d)

Average rate for the reaction

13.
Equilibrium is a __________ process
a)
Static
b)
Dynamic
c)
Probabilistic
d)
Fictitious
14.

 Consider the hypothetical reaction of A transforming to B. Express the rate in terms of the disappearance of A.

a)

rate = −Δ[A]Δtrate\ =\ -\frac{\Delta\left[A\right]}{\Delta t}  

b)

rate = Δ[A]Δtrate\ =\ \frac{\Delta\left[A\right]}{\Delta t}  

c)

rate = Δ[A]Δ[B]rate\ =\ \frac{\Delta\left[A\right]}{\Delta\left[B\right]}  

d)

rate = [A]krate\ =\ \frac{\left[A\right]}{k}  

15.
A possible rate law for a third overall order of a reaction is __________________
a)
Rate = k [A]2[B]2
b)
Rate = k [A][B]3
c)
Rate = k [A]3 [B]
d)
Rate = k [A]2[B]
16.
A reaction has the rate law: Rate = k [A][B].
What will happen to the rate of reaction if the concentration of A is doubled and the concentration of B is tripled?
a)
increases by a factor of 3
b)
increases by a factor of 4
c)
increases by a factor of 5
d)
increases by a factor of 6
17.
The rate law for the reaction 2NO(g) + O2(g) → 2NO2(g) is first order in O2 and third order overall. What is the rate law for the reaction?
a)
Rate = k [NO]2[O2]2
b)
Rate = k [NO]1[O2]2
c)
Rate = k [NO]2[O2]1
d)
Rate = k [2NO]2[O2]1
18.
Which two trials would you use to find the rate exponent for A?
a)
trials 1 and 2
b)
trials 1 and 3
c)
trials 2 and 3
19.
The rate law of any chemical reaction 
a)
must be determined experimentally
b)
can be deduced based on the stoichiometry of the reaction
c)
changes based on the condition of the experiment
d)
I don't know
20.
Find the order for F2 and CIO2 using data shown below.
a)
(F2 - 2nd order) (CIO2 - 1st order)
b)
(F2 - 1st order) (CIO2 - 1st order)
c)
(F2 - 1st order) (CIO2 - 2nd order)
d)
(F2 - 2nd order) (CIO2 - 2nd order)
21.
The following data were measured for the reaction BF3(g) + NH3(g) —> F3BNH3(g)
What is the rate law for the reaction? 
a)
R=K[NH3]
b)
R=K[BF3]2[NH3]
c)
R=K[BF3][NH3]
d)
R=K[BF3][NH3]2
22.
The only factor that can change the value of k is:
a)
concentration
b)
a catalyst
c)
surface area
d)
temperature
23.
Which trial do you insert into the rate law to find k (rate = k [A]m[B]n)?
a)
trial 1
b)
trial 2
c)
trial 3
d)
any trial will work
24.
At what time (in seconds) is equilibrium established?
a)

1 second

b)

3 seconds

c)

8 seconds

d)

15 seconds

25.
Le Chaltelier's Principle states that if a chemical system at equilibrium is stressed,
a)
the system will adjust to increase the stress
b)
the system will adjust to reduce the stress
c)
the system will not adjust
26.
For the reaction...
SO2(g) + O2(g) <−>  SO3(g)
If the concentration of SO2(g)  is increased, the equilibrium of the reaction will ___________.
a)
shift to the left
b)
shift to the right
c)
not shift
27.
For the reaction...
SO2(g) + O2(g) <−>  SO3(g)
If the equilibrium shifts to the right, the concentration of O2(g) will ___________.
a)
increase
b)
decrease
c)
remain the same
28.
For the reaction...
heat  +  N2(g)  +  O2(g)  <−>  2NO(g)
If the heat is removed to the chemical system, the equilibrium will _______.
a)
shift to the left
b)
shift to the right
c)
not shift
29.
For the reaction...
N2 (g) +  3 H2 (g) <−> 2 NH3 (g)

If the pressure in the system is increased, the reaction will __________________.
a)
 shift to the left
b)
shift to the right
c)
not shift
30.
What would happen to the position of the equilibrium when Oxygen is added to the system?
 2SO3(g) ⇋ 2SO2(g) + O2(g) 
a)
SO3 will increase 
b)
SO3 will decrease 
c)
SO2 will increase
d)
none of the above
31.

Which is NOT a way to stress a closed chemical system at equilibrium?

a)

change temperature

b)

add a reactant

c)

take away a chemical in the reaction

d)

add a catalyst

32.

Increasing the pressure on an equilibrium system will

a)

shift the reaction to the side with more moles of chemicals

b)

shift the reaction to the side with more moles of gas

c)

shift the reaction to the side with fewer moles of gas

d)

shift the reaction to the side with fewer moles of chemicals

33.

What type of reactions can change products back to the reactants?

a)

Reversible reactions

b)

Irreversible reactions

c)

Combustion reactions

d)

Combination reactions

34.

If a reversible reaction is exothermic in the forward direction, it will be ...

a)

exothermic in the reverse direction

b)

endothermic in the forward direction too

c)

endothermic in the reverse direction

d)

not involve energy in reverse direction

35.
Which of these is NOT a reversible change?
a)
Water to Ice
b)
Juice to ice lolly
c)
Cookie Dough to Cookie
d)
Melting Chocolate
36.
Increase in temperature of the reactants can do one of the following
a)
Slow collision frequency
b)
Allow less effective collision between the particles
c)
Cause particles to lose speed
d)

Increase the number of collision between the particles thus increasing the rate.

37.

Heat + 1 N2O4 → 2 NO2


What will happen when the temperature is increased?

a)

Position of equilibrium will shift to left and become lighter in color

b)

Position of equilibrium will shift to right and become more brown

c)

No change in position of equilibrium

d)

Position of equilibrium will shift to right and become lighter in color

38.

2SO2(g)+1O2(g) ⇌ 2SO3(g) + Heat


Increasing the pressure on the system will...

a)

shift equilibrium right

b)

shift equilibrium left

c)

slow rate of reaction

d)

have no change

39.

N2(g) + 3H2(g) ↔ 2 NH3(g) + heat

Removing N2 will cause the equilibrium to:

a)

Shift right

b)

Shift left

c)

Have no change

d)

Speed up

40.
Consider the following reaction:
2SO2(g) + O2(g) <=> 2SO3(g):  ΔΗ = - 197 kJ mol -1
Which of the following will NOT shift the equilibrium position to the right?
a)
Adding more O2
b)
Adding a catalyst
c)
increasing the pressure
d)
Lowering the temperature
41.
Which of the following is NOT true at equilibrium?
a)
The forward and reverse reactions proceed at the same rate.
b)
The concentrations of reactants and products do not change.
c)
The concentration of the reactants is equal to the concentration of the products.
d)
The forward and reverse reactions continue to occur.
42.
For the reaction...
energy +  N2(g)  +  O2(g)  <−>  2NO(g)
If  O2(g) is removed, the  concentration of N2 will _______.
a)
increase
b)
decrease
c)
remain the same
d)
double
43.

A single sided arrow (→), indicates that a reaction is:

a)

Reversible

b)

Irreversible

c)

Not reactive

44.

For the following equilibrium reaction:

N2 (g) + 3 H2 (g) <==> 2 NH3 (g) ΔH=-386 kJ/mol

Predict the direction that the reaction will proceed, or shift, if...

The volume of the container is decreased.

a)

right

b)

left

c)

no effect

45.

For the following equilibrium reaction:

N2 (g) + 3 H2 (g) <==> 2 NH3 (g) ΔH=-386 kJ/mol

Predict the direction that the reaction will proceed, or shift, if...

The reaction is cooled.

a)

right

b)

left

c)

no effect

46.

Which letter shows the activation energy

a)

A

b)

B

c)

C

47.

Which letter shows the heat change?

a)

A

b)

B

c)

C

d)

D

e)

E

48.

Which letter represents the reactants?

a)

A

b)

B

c)

C

d)

D

e)

E

49.

Which letter represents the transition state?

a)

A

b)

B

c)

C

d)

D

e)

E

50.

Is this showing an endothermic or an exothermic reaction?

a)

Endothermic

b)

Exothermic

51.

An energy profile for a reversible chemical reaction is shown. According to this profile, the activation energy of the REVERSE reaction is equal to

a)
D
b)
C - B
c)
A - B
d)
C- D
52.

When surface area is decreased the rate of reaction...

a)

Decreases, because there are LESS possible sites for correct collisions

b)

Increases, because there are LESS possible sites for correct collisions

c)

Decreases, because there are MORE possible sites for correct collisions

d)

Increases, because there are MORE possible sites for correct collisions

53.
Consider the following energy profile diagram for a reaction represented by the equation X+Y→Z
Which one of the following provides the correct values of the activation energy (in kJ mol-1) and the ΔH (in kJ mol-1) for the reaction
a)
Activation Energy = +75; ΔH = +100 
b)
Activation Energy = +100; ΔH = +175
c)
Activation Energy = +175; ΔH = +100
d)
Activation Energy = +200; ΔH = -125
54.

Which curve on the diagram represents the catalyzed reaction?

a)

red curve

b)

blue curve

55.
In which experiment is the rate of reaction between hydrochloric acid and calcium carbonate slowest? 
a)
A
b)
B
c)
C
d)
D
56.

Which of the following is true?

a)

The reaction rate of the diagram on the left would be greater because there are more collisions that will happen because of greater surface area.

b)

The reaction rate of the diagram on the right would be greater because there are more collisions that will happen because of lesser surface area.

c)

The reaction rate of the diagram on the right would be greater because there are more collisions that will happen because of greater surface area.

d)

The reaction rate of the diagram on the left would be greater because there are more collisions that will happen because of lesser surface area.

57.

In which container would you expect a higher reaction rate, and why? (Note: The number of particles is the same in both containers.)

a)

The left would have a higher reaction rate because it has a greater volume and more collisions will happen.

b)

The right would have a higher reaction rate because it has a greater volume and more collisions will happen.

c)

The left would have a higher reaction rate because it has a lesser volume and more collisions will happen.

d)

The right would have a higher reaction rate because it has a lesser volume and more collisions wil happen.

58.

In a chemical equilibrium, what happens to the concentrations of reactants and products over time?

a)

They fluctuate

b)

They remain constant

c)

They decrease

d)

They increase

59.
Which of these will NOT speed up the rate of reaction between a strip of magnesium and hydrochloric acid?
a)
tightly coil up the strip of magnesium
b)
cut up the strip of magnesium
c)
increase the concentration of the hydrocholoric acid
d)
increase the temperature of the hydrocholoric acid
60.

Which of the following are true when a catalyst is used in a chemical reaction?

a)
  • Enthalpy of reaction is lower.
  • Activation energy for the reaction is lower.
b)
  • Enthalpy of reaction is same.
  • Activation energy for the reaction is lower.
c)
  • Enthalpy of reaction is the lower.
  • Activation energy for the reaction is same.
d)
  • Enthalpy of the reaction is same.
  • Activation energy for the reaction is same.
61.

Consider the reaction between solid CaCO3 and aqueous HCl. The reaction will be sped up by an increase in which of the following?

I. Concentration of HCl II. Size of the CaCO3 particles III. Temperature

a)

I only

b)

I and III only

c)

II and III only

d)

I, II, and III

62.

Which of the quantities in the enthalpy level diagram below is (are) affected by the use of a catalyst?

a)

I only

b)

III only

c)

I and II only

d)

II and III only

63.

What happens to the rate constant (k) and activation energy (Ea) of a reaction when the temperature is increased?

a)

k increases and Ea is unaffected

b)

k decreases and Ea is unaffected

c)

Ea increases and k is unaffected

d)

Ea decreases and k is unaffected

64.

In general, the rate of a reaction can be increased by all of the following except

a)

Increasing the temperature

b)

Increasing the activation energy

c)

Increasing the concentration of reactants

d)

Increasing the surface area of reactants

65.

Given the reaction


S(s) + O2(g) --> SO2(g) + energy


Which diagram best represents the potential energy changes for this reaction?

a)

a

b)

b

c)

c

d)

d

66.

Given the potential energy diagram for the chemical reaction:


Which statement correctly describes the energy changes that occur in the forward reaction

a)

The activation energy is 50kJ and the reaction is exothermic

b)

The activation energy is 50kJ and the reaction is endothermic

c)

The activation energy is 10kJ and the reaction is exothermic

d)

The activation energy is 10kJ and the reaction is endothermic

67.
When following system is disturbed by addition of Hydrogen gas to the system container how does the system act?
H2(g) + l2(g) ↔ 2HI(g)
a)

System shifts reactants side

b)
System shifts product side
c)
System does nothing
68.
When following system is disturbed by removing of Hydrogen iodide gas to the system container how does the system act?
H2(g) + l2(g) ↔ 2HI(g)
a)
System shifts product side
b)
System shifts reactant side
c)
System does nothing
69.
When following system is disturbed by heating the system container how does the system act?
H2(g) + l2(g) ↔ 2HI(g)  ΔH= -9.6kj/mol
a)
System shifts product side
b)
System shifts reactant side
c)
System does nothing
70.
When following system is disturbed by addition of catalyst to the system container how does concentration of O2 change?
2SO2(g) + O2(g) ↔ 2SO3(g)  ΔH= +9kj/mol
a)
Increase
b)
Deacrease
c)
No change
71.

The initial-rate data in the table above were obtained for the reaction represented below. What is the experimental rate law for the reaction?

2 NO + O2 →\rightarrow NO2

a)

Rate = k[NO][O2]

b)

Rate = k[NO][O2]2

c)

Rate = k[NO]2[O2]

d)

Rate = k[NO]2[O2]2

72.
What happens to this system if pressure decreases?
CO(g) + H2O(g) ↔ H2(g) + CO2(g)
a)
shifts left
b)
shifts right
c)
no change
73.
Which picture shows how a catalyst would change the rate? 
a)
Option 3
b)
Option 2
c)
Option 1
74.
Ammonia is produced commercially by the Haber reaction:   N2 + 3 H2 -->  2 NH3
The formation of ammonia is favored by
a)
an increase in pressure
b)
a decrease in pressure
c)
removal of N2(g)
d)
removal of H2(g)
75.
Given the reaction at equilibrium:
N2(g) + O2(g) ↔ 2NO(g)
As the concentration of N2(g) increases, the concentration of O2(g) will
a)
decrease
b)
increase
c)
remain the same
76.

H2(g) + Br2(g) + heat ↔ 2HBr(g)

Which stresses will shift the equilibrium to the right?

a)

Increasing, temperature, increasing the [H2], increasing the [Br2], decreasing the [HBr], increasing pressure

b)

decreasing temperature, decreasing the [H2], decreasing the [Br2], increasing the [HBr]

c)

Increasing temperature, increasing the [H2], increasing the [Br2], decreasing the [HBr]

d)

Increasing temperature, decreasing the [H2], increasing the [Br2], increasing the [HBr]

77.

Changes in pressure will only affect substances that are in the ______ state.

a)

solid

b)

gas

c)

liquid

78.

What are the two factors that help determine that equilibrium is reached?

a)

Forward reaction rate is faster than the reverse and the concentrations are equal

b)

Forward and reverse reaction rates are equal and concentrations are equal

c)

Forward and reverse reaction rates are equal and concentrations are constant

79.

Le Chatelier's Principle states that if a chemical system at equilibrium is stressed,

a)

the system will adjust to increase the stress

b)

the system will adjust to reduce the stress

c)

the system will not adjust

80.

Such reactions which continue in both directions are called:

a)

Irreversible reactions

b)

Reversible reactions

c)

Non-reactive reactions

d)

dynamic reactions

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