The observed and normal masses of compound $MX_2$ are $65.6$ and $164$ respectively. The percent degree of ionisation of $MX_2$ is . . . . . . $\%.$ (Nearest integer)

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

Acetic acid dissolved in benzene shows a molecular weight of

Benzoic acid undergoes dimerization in benzene. $x \ g$ of benzoic acid (molar mass $122 \ g \ mol^{-1}$) is dissolved in $49 \ g$ of benzene. The depression in freezing point is $1.12 \ K$. If the degree of association of the acid is $88 \%$,what is the value of $x$? ($K_f$ for benzene $= 4.9 \ K \ kg \ mol^{-1}$)

$20 \ g$ of naphthoic acid $(C_{11}H_8O_2)$ $(M_w = 172 \ g/mol)$ is dissolved in $50 \ g$ of benzene. The freezing point depression of $2 \ K$ is observed for the solution. The Van't Hoff factor $(i)$ will be ($K_f$ for benzene $= 1.72 \ K \ kg \ mol^{-1}$)

The degree of dissociation $(\alpha)$ of a weak electrolyte,$A_xB_y$ is related to van't Hoff factor $(i)$ by the expression