Chemical Equilibrium

Question 1

What is a closed system?

Answer 1

A closed system is one in which mass is conserved inside the system but energy can enter or leave the system freely.

Question 2

What is an open system?

Answer 2

An open system is one in which both energy and its matter can be exchanged between the system and its surroundings.

Question 3

What a reversible reaction?

Answer 3

A reversible reaction is one in which products can be converted back into reactants.

Question 4

Explain Dynamic equilibrium.

Answer 4

Dynamic equilibrium refers to a reversible reaction in which the forward and reverse reactions are taking place at the same rate and hence the concentrations of reactants and products are constant.

Question 5

State Le Châteliers principle.

Answer 5

When an external stress (change in pressure, concentration or temperature) is applied to a system in dynamic chemical equilibrium, the point of equilibrium will change to counteract the stress.

Question 6

What effect will a catalyst have on a system in equilibrium?

Answer 6

No effect. The rates of the forward and reverse reactions will be increased equally and thus there will be no impact on the point of equilibrium.

Question 7

What are the conditions for dynamic equilibrium?

Answer 7

• the system must be closed and a reversible reaction must exist.
• the rate of the forward reaction equals the rate of the reverse reaction.