The buffer solution contains equal concentration of `X^(-)` and HX. The `K_(b)` for `X^(-)` is `10^(-10)`. The pH of the buffer solution is :

Options

A. 4
B. 7
C. 10
D. 14

Answer

A

Explanation

`pH=14-pK_(b)-"log"(["Salt"])/(["Base"])`,
`pK_(b)=10` and `"log"(["Salt"])/(["Base"])=log 1=0`
`therefore pH=14-10=4`.