The molecular weight of $NaCl$ determined by osmotic pressure method will be

The molecular mass of acetic acid $(CH_3COOH)$ dissolved in water is $60$,whereas when dissolved in benzene,it is $120$. This difference in behavior is because:

$0.004 \ M \ Na_2SO_4$ is isotonic with $0.01 \ M$ glucose. The degree of dissociation of $Na_2SO_4$ is ........... $\%$.

$A$ $0.5\%$ solution of potassium chloride was found to freeze at $-0.24^{\circ} C$. The percentage dissociation of potassium chloride is .... (Nearest integer)
(Molal depression constant for water is $1.80\, K\, kg\, mol^{-1}$ and molar mass of $KCl$ is $74.6\, g\, mol^{-1}$)

The freezing point of a solution containing $0.85 \ g$ of $ZnCl_2$ in $125.0 \ g$ of water is $-0.23^\circ C$. The degree of dissociation of this salt is .......... $\%$. (Given: $K_f$ of water $= 1.86 \ K \ kg \ mol^{-1}$,atomic mass of $Zn = 65.3$,$Cl = 35.5$)

The van't Hoff factor $i$ for a compound which undergoes dissociation in one solvent and association in other solvent is respectively