Strength of Acids and Alkalis (3)

The strength of alkali

Depending on their degree of ionisation in water

A strong alkali

Is an alkali that ionises completely in water to produce a high concentration of hydroxide ions, OH–

Example of strong alkalis

Sodium hydroxide, NaOH

The reason which sodium hydroxide, NaOH is a strong alkali (1)

Sodium hydroxide, NaOH is a strong alkali that undergoes complete dissociation when dissolved in water

The reason which sodium hydroxide, NaOH is a strong alkali (2)

Only sodium ions, Na+ and hydroxide ions, OH– are present in the solution

Another name for dissociation

Is also known as ionisation

Complete ionisation of sodium hydroxide solution, NaOH

Weak alkali

Is an alkali that ionises partially in water to produce a low concentration of hydroxide ions, OH–

Example of weak alkalis

Ammonia solution, NH3

The reason which ammonia solution, NH3 is a weak alkali

Ammonia solution, NH3 is a weak alkali because ammonia molecules, NH3 ionise partially in water