wayground logo

Free Printable Worksheets

Font size

S
M
L
XL
Worksheets

Chemical Equilibrium

Total questions: 20

Worksheet time: 24mins

Name
Class
Date
1.
2A + 3B  <---->  2AB
The forward reaction forms the substance __________.
a)
A
b)
B
c)
AB
d)
A + B
2.
For the reaction...
SO2 + O2  <−>  SO3
If the concentration of SOis increased, the equilibrium of the reaction will shift ___________.
a)
left
b)
right
c)
left and right 
d)
neither left nor right
3.
For the reaction...
SO2 + O2 <−>  SO3
If the equilibrium shifts to the right, the concentration of O2 will ___________.
a)
increase
b)
decrease
c)
remain the same
d)
double
4.
For the reaction...
heat  +  N2  +  O2  <−>  2NO
If  NO is removed  from the system, the concentration of N2 will _______.
a)
increase
b)
decrease
c)
remain the same
d)
double
5.
For the reaction...
H2 (g)  + Cl2 (g) <−>  2HCl (g)  +  heat
If the temperature is cooled, the _________ reaction will be favored.
a)
forward
b)
reverse
c)
forward and reverse
6.
For the reaction...
N2 (g) +  3 H2 (g) <−> 2 NH3 (g)

If the pressure in the system is increased,  which substance will increase in concentration?
a)
N2
b)
H2
c)
N2 and H2
d)
NH3
7.

What is the effect of increasing the pressure on the following equilibrium: 2NO(g) + O2 (g) ⇌2NO2(g)?

a)

The yield of NO2 increases

b)

The yield of NO2 decreases

c)

The reaction is slower

d)

The concentration of O2 increases.

8.
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.
9.
At what time the reaction reached equilibrium?
a)
t1
b)
t2
c)
t3
d)
t4
10.
How do catalysts increase the rate of reaction?
a)
The frequency of collisions is the increased
b)
the activation energy is lowered
c)
the energy of collisions is increased
d)
Both the frequency and energy of collisions is increased
11.

At elevated temperatures ammonium carbonate, NH2COONH4, is in equilibrium with NH3 and CO2 according to the equation;

NH2COONH4(s) ↔ 2 NH3(g) + CO2(g)

What is the equilibrium expression for this reaction?

a)

K = 2 [NH3][CO2]

[NH2COONH4]

b)

K = [NH3]2[CO2]

[NH2COONH4]

c)

K = 2 [NH3][CO2]

d)

K = [NH3]2[CO2]

12.
2SO2(g)+O2(g)⇌2SO3(g)
Decreasing volume of container will
a)
shift equilibrium right
b)
shift equilibrium left
c)
change K
d)
have no change
13.

For the following reaction: H2(g) + Cl2 (g) ↔ 2HCl(g), calculate the concentration of HCl when Keq= 2.3x10-5, [H2]= 0.0056mol, [Cl2]= 0.0048mol.

a)

6.2 x 10-10 M

b)

2.5 x 10-5 M

c)

1.1 M

d)

1.2 M

14.

PCl3 (g) + Cl2 (g) ↔ PCl5 (g) + energy

Which of the following causes an increase in the moles of PCl5 present at equilibrium shown?

a)

decreasing the volume of the container

b)

raising the temperature

c)

adding a mole of He gas at constant volume

d)

adding a mole of He gas at constant pressure

15.

What kind of equilibrium does the reaction below show?

H2(g) +I2(g) ↔ 2HI(g)

a)

Heterogeneous equilibrium, all the reactants and products are in the same physical state.

b)

Homogeneous equilibrium, all the reactants and products are in the same physical state.

c)

Heterogeneous equilibrium, the reactants and products are present in more than one physical state

d)

Homogeneous equilibrium, the reactants and products are present in more than one physical state

16.
For the reaction...
heat  +  N2  +  O2  <−>  2NO
If the heat is removed from the chemical system, the concentration of N2 will _______.
a)
increase
b)
decrease
c)
remain the same
d)
double
17.
For the reaction...
H2 (g)  + Cl2 (g) <−>  2HCl (g)  +  heat
If the pressure in the system is increased, the equilibrium will _______.
a)
shift left
b)
shift right
c)
not shift
18.

H2(g)+Cl2(g)⇌2HCl(g)

The forward reaction is exothermic. What will happen to the equilibrium if the temperature is increased?

a)

equilibrium shifts right

b)

equilibrium shifts left

c)

You cannot predict the effect

d)

no change

19.
Identify the labels (a) and (b) on the graph.
a)
a is concentration of reactants and b is the concentration of product
b)
a is concentration of product and b is the concentration of reactant
c)
a is the volume of reactants and b is the volume of product
d)
a the mass of reactants and b is the mass of product
20.
Which of the two graphs reaches equilibrium?
a)
The left one.
b)
The right one.
c)
Both of them.
d)
Neither.