Explain buffer action with example.

Explanation

Let us explain the buffer action in a solution containing `CH_3 COOH and CH_3 COONa.`
The dissociation of the buffer components occurs as below.
`CH_3 COONa_((s)) overset(H_2O(I))(to) CH_3 -COO_((aq))^(-)+Na_((aq))^(+)`
If an acid is added to this mixture. it will be consumed by the conjugate base `CH_3 COO^-` to form the undissociated weak acid i.e, the increase in the concentration of `H^+` does not reduce the pH significantly.
`CH_3 COO_((aq))+H_((aq))^(+) to CH_3 COOH_((aq))`
if a base is added , it will be neutralized by `H_3O^+` and the acetic acid is dissociated to maintain the equilibrium. Hence the pH is not significantly altered.
`OH_((aq))^(-)+H_3O_((aq))^(+) to H_2O(I)`
`CH_3 COOH_((aq)) overset(H_2O(I))( hArr )CH_3 COO_((aq))^(-) +H_3O_((aq))^(+)`
`OH_((aq))+CH_3 COOOH_((aq)) to CH_3 COO_((aq))+H_2O(I)`