Which among the following colligative properties is useful to determine molar masses of very expensive solutes?

At $27^{\circ} C$,the osmotic pressure of a solution containing $4 \ g$ of a non-electrolyte solute in $1.0 \ L$ of solution is $0.4 \ bar$. The molar mass of the solute in $g \ mol^{-1}$ is :
$(R=0.083 \ L \ bar \ K^{-1} \ mol^{-1})$

$A$ $5\% \ (w/v)$ solution of anhydrous $CaCl_2$ at $0^o C$ exerts an osmotic pressure of $15 \ atm$. The degree of dissociation $(\alpha)$ of $CaCl_2$ is ....... $\%$.

The osmotic pressure of a solution is given by the relation

$0.5 \ M$ $P_3Q_2$ $(i = 5)$ and $0.01 \ M$ $M_2N_3$ $(i = 5)$ are separated by a semipermeable membrane $AB$ in an aqueous solution as shown. These solutes react to give a brown color. Due to osmosis,there is:

Which one has the highest osmotic pressure?