Question

The concentration of `[H^(+)]` and concentration of `[OH^(-)]` of a `0.1` aqueous solution of `2%` ionised weak acid is [Ionic product of water `=1xx10^(-14)`]
A. `0.02xx10^(-3)M` and `5xx10^(-11)M`
B. `1xx10^(-3)M` and `3xx10^(-11)M`
C. `2xx10^(-3)M` and `5xx10^(-12)M`
D. `3xx10^(-2)M` and `4xx10^(-13)M`

Answer 1

Correct Answer - C
`[H^(+)]` in monobasic acid
= molarity `xx` degree of ionisation
`=0.1xx(2)/(100)=2xx10^(-3)M`
ionisation constant of water
`K_(w)=(H^(+))(OH^(-))`
`[OH^(-)]=(K_(w))/([H^(+)])=(1xx10^(-14))/(2xx10^(-3))=5xx10^(-12)M`