When $HgI_2$ is added to an aqueous solution of $KI$,then the:

$0.6 \, mL$ of acetic acid $(CH_{3}COOH)$,having density $1.06 \, g \, mL^{-1}$,is dissolved in $1 \, L$ of water. The depression in freezing point observed for this strength of acid was $0.0205^{\circ} \, C$. Calculate the van't Hoff factor and the dissociation constant of acid.

$A$ 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 depression in freezing point of a $NaCl$ solution is $6 \ K$. If $K_f = 1.86 \ K \ kg \ mol^{-1}$ for water,then the amount of $NaCl$ dissolved in $1 \ kg$ of water is ............. $mol$?

The observed osmotic pressure for a $0.10 \ M$ solution of $Fe(NH_4)_2(SO_4)_2$ at $25 \ ^oC$ is $10.8 \ atm$. The expected and experimental (observed) values of van't Hoff factor $(i)$ will be respectively: $(R = 0.082 \ L \ atm \ K^{-1} \ mol^{-1})$

Calculate the amount of $KCl$ $(M_w = 74.5 \ g \ mol^{-1})$ in grams required to depress the freezing point of $1000 \ g$ of water by $2 \ K$. (Given: $K_f = 1.86 \ K \ kg \ mol^{-1}$) (in $.0$)