The pressure required for the reverse osmosis is quite high. For this,which of the following membranes is used?

Solution $A$ is prepared by dissolving $1 \text{ g}$ of a protein (molar mass = $50000 \text{ g mol}^{-1}$) in $0.5 \text{ L}$ of water at $300 \text{ K}$. Its osmotic pressure is $x \text{ bar}$. Solution $B$ is made by dissolving $2 \text{ g}$ of the same protein in $1 \text{ L}$ of water at $300 \text{ K}$. The osmotic pressure of solution $B$ is $y \text{ bar}$. The entire solution of $A$ is mixed with the entire solution of $B$ at the same temperature. The osmotic pressure of the resultant solution is $z \text{ bar}$. $x, y$ and $z$ respectively are: $(R = 0.083 \text{ L bar mol}^{-1} \text{ K}^{-1})$

$A$ solution containing $10 \, g \, dm^{-3}$ of urea $(M.wt = 60)$ 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 urea contains $8.6 \ g/L$ (mol. wt. $60.0$). It is isotonic with a $5\%$ solution of a non-volatile solute. The molecular weight of the solute will be:

What is a semi-permeable membrane? Give examples.

$A$ $0.002 \, M$ solution of $NaCl$ having a degree of dissociation of $90 \%$ at $27 \, ^{\circ}C$ has an osmotic pressure equal to: