When acetic acid is dissolved in benzene,its molecular mass:

$2 \ g$ of benzoic acid $(M_w = 122 \ g/mol)$ dissolved in $25 \ g$ of $C_6H_6$ shows a depression in freezing point equal to $1.62 \ K$. Given $K_f (C_6H_6) = 4.9 \ K \ kg \ mol^{-1}$. If the acid forms a dimer in the solution,then the percentage association of the acid is $......... \%$.

The experimentally determined molar mass of a non-volatile solute, $BaCl_2$, in water by Cottrell's method, is

$0.004 \ M \ Na_2SO_4$ is isotonic with $0.01 \ M$ glucose. The degree of dissociation of $Na_2SO_4$ is ........... $\%$.

Determine the degree of association (polymerization) for the reaction in aqueous solution $6 HCHO \rightleftharpoons C_6H_{12}O_6$. If the observed (mean) molar mass of the mixture is $150 \ g/mol$. (Given: Molar mass of $HCHO = 30 \ g/mol$)

$0.2$ molal aqueous solution of $KCl$ freezes at $-0.680^{\circ} C$. Calculate van't Hoff factor for this solution. $(K_{f} = 1.86 \ K \ kg \ mol^{-1})$