Which one of the following $0.10 \ M$ aqueous solutions will exhibit the largest freezing point depression?

Of the following four aqueous solutions,the total number of those solutions whose freezing point is lower than that of $0.10 \, M \, C_{2}H_{5}OH$ is (Integer answer).
$(i)$ $0.10 \, M \, Ba_{3}(PO_{4})_{2}$
$(ii)$ $0.10 \, M \, Na_{2}SO_{4}$
$(iii)$ $0.10 \, M \, KCl$
$(iv)$ $0.10 \, M \, Li_{3}PO_{4}$

Calculate the depression in the freezing point of water when $10 \ g$ of $CH_3CH_2CHClCOOH$ is added to $250 \ g$ of water. $K_a = 1.4 \times 10^{-3}$,$K_f = 1.86 \ K \ kg \ mol^{-1}$

If sodium sulfate $(Na_2SO_4)$ undergoes complete dissociation into its constituent ions in an aqueous solution,what will be the depression in freezing point $(\Delta T_f)$ when $0.01 \ mol$ of sodium sulfate is dissolved in $1 \ kg$ of water (in $K$)? (Given: $K_f = 1.86 \ K \ kg \ mol^{-1}$)

Carnallite in solution in $H_2O$,shows the properties of

For a given electrolyte $A_xB_y$,the relationship between the degree of dissociation '$\alpha$' and the van't Hoff factor '$i$' is ........