$=1.3$
$\%$ increase $=\frac{\left(\Delta T _{ f }\right)_{ obs }-\left(\Delta T _{ f }\right)_{ cal }}{\left(\Delta T _{ f }\right)_{ cal }} \times 100$
$=\frac{K_f \times i \times m-K_f \times m}{K_f \times m} \times 100$
$=\frac{i-1}{1} \times 100=30 \%$
(આપેલ, $K_f = 5\,K\, kg\,mol^{-1},$ બેન્ઝોઇક એસિડનું મોલર દળ $= 122\,g\,mol^{-1}$ )
[આપેલ : એસિટિક એસિડની ધનતા $1.02\,g\,mL ^{-1}$ છે.એસિટિક એસિડનું મોલર દળ $60\,g\,mol ^{-1}$ છે.$\left. K _{f}\left( H _{2} O \right)=1.85 K\,kg\,mol ^{-1}, K _{f}\left( H _{2} O \right)=1.85\,K\,kg\,mol ^{-1}\right]$