The dissociation constants for acetic acid and HCN at `25^(@)C` are `1.5xx10^(-5)` and `4.5xx10^(-10)` , respectively. The equilibrium constant for the equilibirum `CN^(-) + CH_(3)COOHhArr HCN + CH_(3)COO^(-)` would be

Options

A. `3.0 xx10^5`
B. `3.0 xx10^(-5)`
C. `3.0 xx10^(-4)`
D. `3.0 xx10^(4)`

Answer

D

Explanation

`CH_3 COOH hArr CH_3 COO^(-) + H^(+) , K_(alpha) = 1.5 xx10^(-5)`
`H^(+)+CN^(-)hArrHCN,1/K_(alpha)=1/(4.5 xx10^(-10))`
`:. K_(alpha)` for `CN^(-)+ CH_3COOHhArr CH_(3)COO^(-)+HCN` is `(1.5xx10^(-5))/(4.5 xx10^(-10))=1/3 xx10^5 =3.33 xx10^4`