Solutions: JEE Main 2025 Chemistry question

$\mathrm{HA(aq) \rightleftharpoons H^+(aq) + A^-(aq)}$. The freezing point depression of a 0.1 m aqueous solution of a monobasic weak acid HA is 0.20 °C. The dissociation constant for the acid is. Given: $K_f(\mathrm{H_2O}) = 1.8$ K kg mol$^{-1}$, molality $\equiv$ molarity