$A$ graph of osmotic pressure $(\pi)$ vs molarity $(M)$ of an aqueous solution of $NaCl$ at room temperature is given below. The slope of the line represents :-

When kept in water,a raisin swells in size. Name and explain the phenomenon involved with the help of a diagram. Give three applications of the phenomenon.

Assuming the compounds to be completely dissociated in aqueous solution, identify the pair of the solutions that can be expected to be isotonic at the same temperature.

If $250 \ cm^3$ of an aqueous solution containing $0.73 \ g$ of a protein $A$ is isotonic with one litre of another aqueous solution containing $1.65 \ g$ of a protein $B,$ at $298 \ K,$ the ratio of the molecular masses of $A$ and $B$ is..........$\times 10^{-2}$ (to the nearest integer).

$0.6 \ g$ of a solute is dissolved in $0.1 \ L$ of a solvent which develops an osmotic pressure of $1.23 \ atm$ at $27 \ ^\circ C$. The molecular mass of the substance is ........ $g \ mol^{-1}$.

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