A certain buffer solution contains equal concentartion of `X^(Theta)` and `HX`. The `K_(b)` for `X^(Theta)` is `10^(-10)`. The `pH` of the buffer is

Options

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

Answer

A

Explanation

`K_(b) "for" X^(Theta) = 10^(-10)`
`rArr K_(a) for HX = (K_(w))/(K_(b)(X^(Theta))) =(10^(-14))/(10^(-10)) = 10^(-4)`
`rArr pH = pK_(a) +"log" ([X^(Theta)])/([HX]) =pK_(a) = 4`