Question

The buffering action of an acidic buffer is maximum when its pH equals to
A. 5
B. 7
C. 1
D. `pK_(a)`

Answer 1

Correct Answer - D
Buffer capacity of an acidic buffer is maximum when the ratio of HA to `A^(-)` is unity since, pH of acidi buffer ltbr. `=pK_(a) + log.([A^(-)])/([HA])`
For maximum buffer capacity `[A^(-)] = [HA^(-)]`
`:. pH = pK_(a)`