What is the `K_(b)` of weak base that produce one OH-ion if a 0.05 M solution is 2.5% ionised ?

Options

A. `7.8xx10^(-8)`
B. `1.6xx10^(-6)`
C. `3.1xx10^(-5)`
D. `1.2xx10^(-3)`

Answer

C

Explanation

One `OH^(-)` molecule means monoacidis base.
Like `NH_(4)` OHorBOH
`BOH hArr B^(+)rArrKb`
`K_(b)=0.05xx((2.5)/(100))^(2)rArr3.1xx10^(-5)`