Question

Explain Buffer action with suitable example.

Answer 1

Buffer action: 

1. Let us consider buffer solution containing CH₃COOH and CH₃COO Na. The dissociation the buffer components occur as below.

2. If an acid is added to this mixture, it will be consumed by the conjugate base CH₃COO^- to form undissociated weak acid. i.e., the increase in the concentration of H⁺ does not reduce the pH significantly.

CH₃COO_(aq)^- + H_(aq)⁺ → CH₃COOH_(aq)

3. If a base is added, it will be neutralised by H₃O and the acetic acid is dissociated to maintain the equilibrium. Hence the pH is not altered.

4. On the addition of an acid (or) base to a buffer solution, there will be no change in its pH value. Because the buffer solution should contain both acidic as well as basic components so as to neutralise the effect of added acid (or) base at the same time, these components should not consume each other.