A cetrain buffer solution contains equal concentration of `X^(-)` and HX. Calculate pH of buffer. `(K_(b)for X^(-)is 10^(-10))`

Options

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

Answer

A

Explanation

`pH= -log K_(a)+log ([Sal t])/([Acid])`
`= -log 10^(-4)+log(1)/(1)=4`
`[Si nce K_(a)xxK_(b)=10^(-14)`
Given `K_(b)=10^(-10)`
`:. K_(a)=10^(-4)]`