The phenomenon of osmosis involves:

The osmotic pressure of sea water is $1.05 \ atm$. Four experiments were carried out as shown in the table below. In which of the following experiments can pure water be obtained in part-$II$ of the vessel?
| Experiment | Pressure applied on part-$I$ $(atm)$ | Pressure applied on part-$II$ $(atm)$ |
| :--- | :--- | :--- |
| $I$ | $2.0$ | $1.0$ |
| $II$ | $1.0$ | $2.0$ |
| $III$ | $3.0$ | $1.0$ |
| $IV$ | $1.0$ | $1.0$ |

$A$ solution containing $10 \ g$ per $dm^3$ of urea (molecular mass $= 60 \ g \ mol^{-1}$) is isotonic with a $5 \%$ solution of a non-volatile solute. The molecular mass of this non-volatile solute is ........ $g \ mol^{-1}$.

$A$ solution of sucrose (molar mass $= 342 \ g \ mol^{-1}$) is prepared by dissolving $68.4 \ g$ of it per litre of the solution. What is its osmotic pressure in $atm$ at $273 \ K$? (Given: $R = 0.082 \ L \ atm \ K^{-1} \ mol^{-1}$)

If a solution has an osmotic pressure of $0.82 \ bar$ at $27 \ ^oC$,find the concentration of such a solution. (in $M$)

$3 \ mL$ of solution was made by dissolving $20 \ mg$ of protein at $0^{\circ} C$. The osmotic pressure of the resulting solution is $3.8 \ torr$. The molecular weight of the protein is approximately $(g/mol)$