Accumulation of lactic acid `(HC_(3)H_(5)O_(3))`, a monobasic acid in tissues leads to pain and a feeling of fatigue. In a 0.10 M aqueous solution, lactic acid is `3.7%` dissociates. The value of dissociation constant Ka, for this acid will be

Options

A. `1.4 xx 10^(-5)`
B. `1.4 xx 10^(-4)`
C. `3.7 xx 10^(-4)`
D. `2.8 xx 10^(-4)`

Answer

B

Explanation

`alpha = sqrt((K_(a))/C)`
`alpha^(2) = (K_(a))/C or K_(a) = Calpha^(2)`
`K_(a) = 0.10 xx ((3.7)/100)^(2)`
`K_(a) = 1.4 xx 10^(-4)`