If 0.1 M of a weak monobasic acid is taken and its percentage degree of ionisation is `1.34 %`, then calculate its ionisation constant.

Options

A. `0.8 xx 10^(-5)`
B. `1.79 xx 10^(-5)`
C. `0.182 xx 10^(-5)`
D. None of these

Answer

B

Explanation

`alpha =1.34 %=(1.34)/(100)=1.34 xx 10^(-2)`
`C=0.1 mol L^(-1)`
`K_(a)=C alpha^(2) =0.1 xx (1.34 xx 10^(-2))^(2)`
`=1.7956 xx 10^(-5)`