Question

Why are buffers weak acids and bases?

Answer 1

Buffer: Buffer is a type of solution which resist any change in pH of the solution even when a small amount of acid and bases are added to it.

Types of buffer:

The buffer solutions are mainly of two types:

Solution of single substance: The solution of a salt of weak acid and a weak acid acts as a buffer.

Example: Ammonium acetate$\left({\mathrm{CH}}_3{\mathrm{CONH}}_4\right)$

Solution of mixture:

Acidic buffer: The solution of a mixture of a weak acid and salt of that weak acid with a strong base acts as an acidic buffer.

Example: Acetic acid + Sodium acetate$({\mathrm{CH}}_3\mathrm{COOH}+{\mathrm{CH}}_3\mathrm{COONa})$

Basic buffer: The solution of a mixture of a weak base and salt of that weak base with a strong acid acts as a basic buffer.

Example: Ammonium hydroxide + Ammonium chloride$({\mathrm{NH}}_4\mathrm{OH}+{\mathrm{NH}}_4\mathrm{Cl})$