Which of the following is an excellent semipermeable membrane?

$A$ solution of a nonvolatile solute is obtained by dissolving $0.8 \ g$ in $0.3 \ dm^3$ of water. The solution has an osmotic pressure of $0.2 \ atm$ at $300 \ K$. Calculate the molar mass of the solute. $[R = 0.082 \ atm \ dm^3 \ K^{-1} \ mol^{-1}]$

$x \ g$ of $MgSO_4$ $(i=1.8)$ in $2.5 \ L$ of solution has an osmotic pressure of $2.463 \ atm$ at $27^{\circ} C$. What is the value of $x$ in $g$?

What is the numerical value of osmotic pressure of $1 \ M$ urea solution if the numerical value of osmotic pressure of $0.5 \ M$ urea solution is $x$?

Assume a living cell with $0.9 \% (\omega / \omega)$ of glucose solution (aqueous). This cell is immersed in another solution having equal mole fraction of glucose and water. (Consider the data up to the first decimal place only). The cell will :

$A$ $3\% \, w/v$ aqueous solution of urea is isotonic with a $5\% \, w/v$ aqueous solution of another solute. Assuming the van't Hoff factor for the solute is $1.0$,calculate the molar mass of the solute in $g/mol$.