25 mL of an aqueous solution of KCl was found to require 20 mL of $1 \mathrm{M} \mathrm{AgNO}_3$ solution when titrated using $\mathrm{K}_2 \mathrm{CrO}_4$ as an indicator. What is the depression in freezing point of KCl solution of the given concentration? ____________ (Nearest integer). (Given :$\mathrm{K}_{\mathrm{f}}=2.0 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$) Assume 1) 100% ionization and 2) density of the aqueous solution as $1 \mathrm{~g} \mathrm{~mL}^{-1}$