The depression in freezing point observed for a formic acid solution of concentration \( 0.5 \,\mathrm{mL \, L^{-1}} \) is \( 0.0405^\circ \mathrm{C} \). Density of formic acid is \( 1.05 \,\mathrm{g \, mL^{-1}} \). The Van’t Hoff factor of the formic acid solution is nearly : (Given for water \( k_f = 1.86 \,\mathrm{kg \, mol^{-1}} \))