Chemical Equilibrium: Quiz

Question 1

Which states that when a system at equilibrium is subjected to change, the system, if possible, shifts its equilibrium position so at to minimize the effect of the change?
Chemical Equilibrium
Equilibrium Constant
Reaction Quotient
Le Chatelier’s Principle

Answer 1

Le Chatelier’s Principle

Question 2

What is the conventional equilibrium constant expression for this system: 2SO3(g) ⇌ 2SO2(g) + O2(g)?

[SO2]2/[SO3]
[SO3]2/[SO3]2[O2]
[SO2][O2]
[SO2]2[O2]/[SO3]2

Answer 2

[SO2]2[O2]/[SO3]2

Question 3

What factor can be increased to provide more collisions for gases only?
Pressure
Concentration
Adding a catalyst
Temperature

Answer 3

Pressure

Question 4

Which will NOT affect systems in equilibrium?
Changing pressure
Changing concentration
Changing temperature
Adding a catalyst

Answer 4

Adding a catalyst

Question 5

While all different types of physical states can be present in a chemical equation, the incorporation of __________ is not expressed in the equilibrium constant expression.
Solid and liquid
Gases
Liquid
Solid

Answer 5

Solid and liquid

Question 6

When writing an equilibrium expression, the coefficients from the balanced equation becomes the ______.
Exponents of the concentration terms
Subscripts of the concentration terms
Factors of the concentration terms
Divisor of concentration terms

Answer 6

Exponents of the concentration terms

Question 7

Which of the following statements are true? An equilibrium constant K for a reaction tells us:

I. If you know the actual concentrations, comparison to “K” can tell you whether the system is at equilibrium or not

II. If the system is not at equilibrium initially, comparing the actual concentration to “K” can tell you which direction the reaction will go to achieve equilibrium. (In other words, whether the reaction will go more towards the right side from what it is initially, or whether it will go more towards the left side.)

III. K can tell you whether products or reactants predominate at equilibrium

IV. K can tell you what the mechanism is.

V. K can tell you what the rate law is

I only
I, II and III only
I and III only
IV only

Answer 7

I, II and III only

Question 8

A large equilibrium constant value means that the _______.
Reaction favors the reactants
Reaction can never attain equilibrium
Reaction favors the products
Reaction is at completion

Answer 8

Reaction favors the products

Question 9

H2(g) + I2(g) ⇌ 2HI(g)

If additional I2(g) is added to the reaction vessel, the equilibrium will

Shift to the left
Cannot be determined
Shift to the right
Remain at the same concentrations

Answer 9

Shift to the right

Question 10

At a particular temperature, how many equilibrium constants can exist?
9
0
3
1

Answer 10

1

Question 11

Ammonia is produced commercially by the Haber reaction:

N2(g) + 3H2(g) ⇌ 2NH3(g)

The formation of ammonia is favored by _________.

a decrease in pressure
removal of H2(g)
an increase in pressure
removal of N2(g)

Answer 11

an increase in pressure

Question 12

The equilibrium constant is always written as a ratio of _________.
summation of products and reactants
reactants over products
products multiplied by reactants
products over reactants

Answer 12

products over reactants

Question 13

For the equilibrium, 2NOCl(g) ⇌ 2NO(g) + Cl2(g) the value of the equilibrium constant, Kc is 3×10–6 at 1069 K. Calculate the Kp for the reaction at this temperature?

2.6 × 10-4
7.5 × 10-5
1.75 × 10-4
3.9 × 10-5

Answer 13

2.6 × 10-4