Solutions: JEE Main 2023 Chemistry question

25 mL of an aqueous solution of KCl was found to require 20 mL of 1 M $\mathrm{AgNO_3}$ solution when titrated using $\mathrm{K_2CrO_4}$ as an indicator. What is the depression in freezing point of KCl solution of the given concentration? _________ (Nearest integer). (Given : $\mathrm{K_f=2.0~K~kg~mol^{-1}}$) Assume 1) 100% ionization and 2) density of the aqueous solution as 1 g mL$^{-1}$