Introduction

Question 1

We have seen that chemical reactions can vary greatly in the _____ of the reaction. In the same way, chemical reactions can differ in the _____ of reaction. This means that some reactions use up all their _____ and form products, while other reactions will have both reactants and products present no matter how long you wait.

Answer 1

Rate
Extent
Reactants

Question 2

What is a reversible reaction?

Answer 2

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

Question 3

What is dynamic equilibrium?

Answer 3

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

Question 4

List the external factors which change the equilibrium position of a particular reaction viz: (3)

Answer 4

temperature
pressure
concentration

Question 5

List an example of dynamic equilibrium.

Answer 5

Water in a beaker can evaporate completely over time. Water in a covered beaker evaporates quickly at first, but after a while evaporation appears to stop. As the water in the enclosed space evaporates, the concentration of the water vapour increases and as a result, condensation increases. Eventually a condition is reached where the rate of evaporation is equal to the rate of condensation.

A state of dynamic equilibrium is said to exist between the liquid and vapour phase.