Write the value of the van't Hoff factor $(i)$ for $K_{2}SO_{4}$ and $K_{4}[Fe(CN)_{6}]$.

$0.8 \ mL$ of acetic acid of density $1.06 \ g \ mL^{-1}$ when dissolved in $1 \ kg$ of water causes a depression in freezing point by $0.0325^{\circ} C$. The Van't Hoff factor is:
$(K_{f} \text{ of } H_2O = 1.86 \ K \ kg \ mol^{-1})$

$0.5 \ m$ aqueous solution of a weak acid $(HX)$ is $20 \%$ ionized. If $K_{f}$ of water is $1.86 \ K \ kg \ mol^{-1}$,the lowering in freezing point of the solution is: (in $K$)

Which of the following aqueous solutions has the highest boiling point?

For $0.01 \ M$ solutions of urea,$NaCl$,and $Na_2SO_4$,the ratio of their depression in freezing point is .......

The depression in freezing point for $0.01 \ m$ aqueous solution of $K_{x}[Fe(CN)_6]$ is $0.0744 \ K$. The molal depression constant for solvent is $1.86 \ K \ kg \ mol^{-1}$. If the solute undergoes complete dissociation,what is the correct molecular formula for the solute?