Which statement is wrong regarding osmotic pressure $P$,volume $V$,and temperature $T$?

What is the osmotic pressure $(\pi)$ of a $0.02 \ M$ solution of $NaCl$ (in $RT$)?

What is the osmotic pressure of a solution of $1.7 \ g$ of $CaCl_2$ in $1.25 \ dm^3$ of water at $300 \ K$,if the van't Hoff factor and molar mass of $CaCl_2$ are $2.47$ and $111 \ g \ mol^{-1}$ respectively (in $atm$)? $[R=0.082 \ dm^3 \ atm \ mol^{-1} \ K^{-1}]$

$A$ solution of $8 \ g$ of a certain organic compound in $2 \ dm^3$ of water develops an osmotic pressure of $0.6 \ atm$ at $300 \ K$. Calculate the molar mass of the compound. $\left[R = 0.082 \ atm \ dm^3 \ K^{-1} \ mol^{-1}\right]$

Given below are two statements:
Statement $I$: $H_2O$ molecules move from the chamber $1$ to chamber $2$.
Statement $II$: The osmotic pressure of a solution prepared by dissolving $50 \text{ mg}$ of potassium sulphate (molar mass = $174 \text{ g/mol}$) in $2 \text{ L}$ of water (at $27^{\circ}C$) is $0.0107 \text{ bar}$. (Given: $R = 0.083 \text{ dm}^3 \text{ bar K}^{-1} \text{ mol}^{-1}$ and assume complete dissociation of electrolyte).
In the light of the above statements,choose the correct answer from the options given below:

Explain reverse osmosis and the purification of water.