Question

$20 \%$ of acetic acid is dissociated when its $5\, g$ is added to $500 \, mL$ of water The depression in freezing point of such water is ____ $\times 10^{-3}{ }^{\circ} C$ Atomic mass of $C , H$ and $O$ are 12,1 and 16 amu respectively [Given : Molal depression constant and density of water are $186 \,K \,kg\, mol ^{-1}$ and $1 \,g \,cm ^{-3}$ respectively

Answer 1

The correct answer is 372.
i=1+(n−1)α
(i=1+0.2(2−1)=1.2
ΔTf​=iKf​m
ΔTf​=1.2×1.86×60×5005×1000​
Δtf​=3.72
ΔTf​=372×10−2