Arrhenius Theory of Electrolytic Dissociation

To explain the phenomenon of electrolysis and the mechanism of electrolytic dissociation. Arrhenius put forward his theory which states that:

1. Electrolytes (acids, bases and salts) in solution or a fused state dissociate into electrically charged particles called ions when electricity is conducted through them.

2. Each molecule of the electrolyte usually gives rise to two kinds of ions carrying equal but opposite charges – +ve ions called cations and -ve ions called anions.

3. Charged ions constantly attract each other and form neutral molecules.

4. Ionisation i.e, dissociation into ions usually increases with dilution and at a particular dilution, equilibrium is attained when the rate of ionisation is equal to the rate of formation of neutral molecules.

5. Atoms and ions of the same element have different physical and chemical properties.