a
\(\text { Mass of } \mathrm{CH}_3 \mathrm{COOH}=\mathrm{V} \times \mathrm{d}\)

\(=5 \mathrm{ml} \times 1.2 \mathrm{~g} / \mathrm{ml}\)

\(=6 \mathrm{gm}\)

\(\mathrm{n}_{\mathrm{CH}_3 \mathrm{COOH}}=\frac{6}{60}=0.1 \mathrm{~mol}\)

\(\mathrm{~m}_{\mathrm{CH}_3 \mathrm{COOH}} \approx \mathrm{M}_{\mathrm{CH}_3 \mathrm{COOH}}=\frac{0.1}{1}=0.1 \mathrm{M}\)

\(\mathrm{CH}_3 \mathrm{COOH} \rightleftharpoons \mathrm{CH}_3 \mathrm{COO}^{-}+\mathrm{H}^{+}\)

\(\mathrm{C}\)

\(\mathrm{C}-\mathrm{C} \alpha\)

\(\mathrm{K}_{\mathrm{a}}=\frac{\mathrm{C} \alpha^2}{1-\alpha}\)

\(1-\alpha \approx 1 \Rightarrow \mathrm{K}_{\mathrm{a}}=\mathrm{C}^2\)

\(\alpha=\sqrt{\frac{\mathrm{Ka}^2}{\mathrm{C}}}=\sqrt{\frac{6.25 \times 10^{-5}}{0.1}}=25 \times 10^{-3}\)

\(\mathrm{~V} . \mathrm{f} .(\mathrm{i})=1+\alpha(\mathrm{n}-1)=1+\alpha(2-1)=1+\alpha\)

\(=1+25 \times 10^{-3}=1.025\)

\(\Delta \mathrm{T}_{\mathrm{r}}=i \mathrm{~K} \mathrm{~m}\)

\(=(1.025)(1.86)(0.1)\)

\(=0.19\)

\(=19 \times 10^{-2}\)