# The dissociation constants for acetic acid and HCN at 25ºC are $1.5\times10^5$ and $4.5\times10^{10}$, respectively. The equilibrium constant for the equilibrium - <br> $CN^{-}+CH_3COOH\rightleftharpoons HCN+CH_3COO^{-}$ <br> would be :
( A ) $3.0\times 10^{–4}$
( B ) $3.0\times 10^{5}$
( C ) $3.0\times 10^{–5}$
( D ) $3.0\times10^{4}$