Determine the expected value of $\Delta T_f$ for $1 \mathrm{~m} \mathrm{CaCl}_2$ solution if 1 m urea solution has $\Delta \mathrm{T}_{\mathrm{f}}$ value ' $x$ ' K .

Calculate van't Hoff factor of aqueous solution of 0.18 m electrolyte that freezes at $-0.54^{\circ} \mathrm{C}$.

$\left(\mathrm{K}_{\mathrm{f}}\right.$ for solvent $\left.=1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\right)$

Calculate the molality of solution of nonvolatile solute if boiling point elevation is 1.75 K .

[ $\mathrm{K}_{\mathrm{b}}$ for solvent $=3 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$ ]

Calculate the relative lowering of vapour pressure of solution containing 3 g urea in 50 g water. [molar mass of urea $=60 \mathrm{~g} \mathrm{~mol}^{-1}$ ]