Specific conductance of `10^(-4)M n`-Butyric acid aqueous solution is `1.9 xx 10^(-9)S m^(-1)`. If molar conductance of n-Butyric acid at infinite dilution is `380 xx 10^(-4) S m^(2) mol^(-1)`, then `K_(a)` for n-Butyric acid is:

Explanation

`^^_(m) = 1000 xx (1.9 xx 10^(-9))/(10^(-4)) = 1.9 xx 10^(-2)`
`alpha = (1.9 xx 10^(-2))/(380 xx 10^(-4)) = 0.5`
`K_(a) = (10^(-4)(0.5)^(2))/(1-0.5) = 5 xx 10^(-5)M`