The freezing point of benzene decreases by $0.45^{\circ}C$ when $0.2\; g \%$ of acetic acid is
added to $20\; g$ of benzene. If acetic acid associates to form a dimer in benzene,percentage association of acetic acid in
benzene will be :
$(Kf$ for benzene=$5.12 \;K \;kg mol^{−1})$
