The osmotic pressure of sea water is 1.05 atm . Four experiments were carried as shown in table. In which of the following experiments, pure water can be obtained in part-II of vessel.

$$ \begin{aligned} &\text { Table }\\ &\begin{array}{ccc} \hline \begin{array}{c} \text { Expt. } \\ \text { No } \end{array} & \begin{array}{c} \text { Pressure applied in } \\ \text { part-1 of vessel } \end{array} & \begin{array}{c} \text { Pressure applied in } \\ \text { part-II of vessel } \end{array} \\ \hline \text { I. } & 10 \mathrm{~atm} & - \\ \hline \text { II. } & - & 10 \mathrm{~atm} \\ \hline \text { III. } & 15 \mathrm{~atm} & - \\ \hline \text { IV. } & - & 15 \mathrm{~atm} \end{array} \end{aligned} $$

The $\Delta T_b$ value for 0.01 m KCl solution is 0.01 K . What is the van't Hoff factor? $$ \left(K_b \text { for water }=0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}\right) $$

200 g of $20 \% \frac{\mathrm{w}}{\mathrm{w}}$ urea solution is mixed with 400 g of $40 \% \frac{w}{w}$ urea solution. What is the weight percentage $\left(\frac{w}{w} \%\right)$ of resultant solution?