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).
$(i)$ $0.10 \, M \, Ba_{3}(PO_{4})_{2}$
$(ii)$ $0.10 \, M \, Na_{2}SO_{4}$
$(iii)$ $0.10 \, M \, KCl$
$(iv)$ $0.10 \, M \, Li_{3}PO_{4}$

The experimental molecular weight of an electrolyte will always be less than its calculated value because the value of Van't Hoff factor $i$ is

$2.0 \, m \, CH_3COOH$ undergoes $100 \%$ dimerization in benzene. It will be isotonic with which of the following?

$A$ solution containing $10 \ g$ of an electrolyte $AB_2$ in $100 \ g$ of water boils at $100.52^{\circ} C$. The degree of ionization of the electrolyte $(\alpha)$ is............ $\times 10^{-1}$.
(nearest integer)
[Given : Molar mass of $AB_2 = 200 \ g \ mol^{-1}$,$K_{b}$ (molal boiling point elevation constant of water) $= 0.52 \ K \ kg \ mol^{-1}$,boiling point of water $= 100^{\circ} C$;
$AB_2$ ionises as $AB_2 \rightarrow A^{2+} + 2B^{-}$]

The van't Hoff factor $(i)$ for a dilute aqueous solution of the strong electrolyte barium hydroxide is

At a certain temperature,the vapour pressure of pure water is $76 \ mm$ of $Hg$. When $1 \ mol$ of $Na_2SO_4$ is dissolved in $36 \ mL$ of water,the vapour pressure of the solution becomes $38 \ mm$ of $Hg$. What is the percentage dissociation of $Na_2SO_4$ in the solution?