An aqueous solution of $0.6 \% (w/v)$ urea is isotonic with which of the following?

At the same temperature,which of the following pairs of solutions will be isotonic?

Which inorganic precipitate acts as a semipermeable membrane,or what is the chemical composition of a semipermeable membrane?

The osmotic pressure of a living cell is $12 \ atm$ at $300 \ K$. The strength of sodium chloride solution that is isotonic with the living cell at this temperature is $...... \ g \ L^{-1}$. (Nearest integer)
Given : $R = 0.08 \ L \ atm \ K^{-1} \ mol^{-1}$
Assume complete dissociation of $NaCl$
(Given : Molar mass of $Na$ and $Cl$ are $23$ and $35.5 \ g \ mol^{-1}$ respectively.)

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-$II$ $(atm)$ |
| :--- | :--- | :--- |
| $I$ | $2.0$ | $1.0$ |
| $II$ | $1.0$ | $2.0$ |
| $III$ | $3.0$ | $1.0$ |
| $IV$ | $1.0$ | $1.0$ |

. . . . . . solution is hypertonic with reference to fluid inside the blood cell.