The solution which consumes `[H^(+)]` or `[OH^(-)]` or both simultaneously from externally added base in order to give negligible change in `pH`, is known as buffer solution. In general, the solution resists the change in pH. Buffer solution does not mean that there does not occur a pH change in pH. Buffer solution des not mean that there does not occur a pH change at all. It implies the pH change occurs but in neglibible amount. There are two types of buffer
(i) Acidic buffer: it is a mixture of weak acid and its salt acid strong base.
(ii) Basic buffer : It is a mixture of weak base and its salt with strong acid.
pH of `0.01 M (NH_(4))_(2)SO_(4)` and `0.02 M NH_(4)OH` buffer (`pK_(a)` of `NH_(4^(+)) = 9.26)` is

Options

A. `4.74 + "log"2`
B. `4.74 - "log" 2`
C. `4.74 + "log" 1`
D. `9.26 + "log" 1`

Answer

D

Explanation

Use Henderson's equation.