A certain buffer solution sontains equal concentration of `X^(-)` and `HX`. The `K_(a)` for `HX` is `10^(-8)`. The of the buffer is

Options

A. `3`
B. `8`
C. `11`
D. `14`

Answer

B

Explanation

It is an acidic buffer. Thus,
`pH=pK_(a)+log.(C_("salt"))/(C_("acid"))`
Since `K_(a)= 10^(-8)` and `C_("salt")=C_("acid",)` we have
`pH=8+log 1= 8+0 = 8`