When $20 \ g$ of naphthoic acid $(C_{11}H_8O_2)$ is dissolved in $50 \ g$ of benzene, a freezing point depression of $2 \ K$ is observed. The van't Hoff factor $(i)$ is [$K_f = 1.72 \ K \ kg \ mol^{-1}$].

The experimental depression in freezing point of a dilute solution is $0.025 \ K$. If the van't Hoff factor $(i)$ is $2.0$, the calculated depression in freezing point (in $K$) is

For an aqueous solution of $FeSO_4$, the experimental molecular mass is found to be $80 \ g/mol$. What is the degree of dissociation of the salt?

When $12.2 \ g$ of benzoic acid is dissolved in $100 \ g$ of benzene, the freezing point of the solution is found to be $-0.93^{\circ} C$ $(K_{f}(\text{benzene}) = 5.12 \ K \ kg \ mol^{-1})$. The number $(n)$ of benzoic acid molecules associated (assuming $100 \ \%$ association) is ........ .

Molecules of benzoic acid $(C_6H_5COOH)$ dimerise in benzene. '$w$' $g$ of the acid dissolved in $30 \ g$ of benzene shows a depression in freezing point equal to $2 \ K.$ If the percentage association of the acid to form dimer in the solution is $80,$ then $w$ is : ............. $g$
(Given that $K_f = 5 \ K \ kg \ mol^{-1},$ Molar mass of benzoic acid $= 122 \ g \ mol^{-1}$ )

The Van't Hoff factor of $BaCl_2$ at a concentration of $0.01 \ M$ is $1.98$. The percentage dissociation of $BaCl_2$ at this concentration will be: (in $\%$)