$A$ solute $A$ dimerizes in water. The boiling point of a $2 \, M$ solution of $A$ is $100.52^{\circ} C$. The percentage association of $A$ is ..... $\%$.
(Round off to the Nearest integer)
[Use : $K_{b}$ for water $= 0.52 \, K \, kg \, mol^{-1}$,Boiling point of water $= 100^{\circ} C$]

$20 \ g$ of naphthoic acid $(C_{11}H_8O_2)$ dissolved in $50 \ g$ of benzene $(K_f = 1.72 \ K \ kg \ mol^{-1})$ shows a depression in freezing point of $2 \ K$. The Van't Hoff factor is?

$75.2 \ g$ of phenol is added to $1 \ kg$ of solvent. The depression in freezing point is $7 \ K$. If phenol undergoes dimerization,calculate the percentage of association. $(K_f = 14 \ K \ kg \ mol^{-1})$

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 $HCHO = 30 \ g/mol$)

The freezing point of a solution containing $0.85 \ g$ of $ZnCl_2$ in $125.0 \ g$ of water is $-0.23^\circ C$. The degree of dissociation of this salt is .......... $\%$. (Given: $K_f$ of water $= 1.86 \ K \ kg \ mol^{-1}$,atomic mass of $Zn = 65.3$,$Cl = 35.5$)

Benzoic acid molecules undergo dimerisation in benzene. $2.44 \ g$ of benzoic acid when dissolved in $30 \ g$ of benzene caused a depression in freezing point of $2 \ K$. What is the percentage of association of it? (Given $K_f(C_6H_6) = 5 \ K \ kg \ mol^{-1}$; molar mass of benzoic acid $= 122 \ g \ mol^{-1}$)