Select the correct statement for the van't Hoff factor $(i)$ of benzoic acid in benzene.

For a $1.5 \, m$ aqueous solution of $Ca(NO_3)_2$,the observed molar mass is $65.4 \, g \, mol^{-1}$ and the theoretical molar mass is $164 \, g \, mol^{-1}$. The degree of dissociation is .............

In an experiment to estimate the molecular weight of benzoic acid by the elevation in boiling point method, the experimental value of the molecular weight was double the actual value. Calculate the degree of association of the dimer.

Phenol dimerised to $60\%$ in a solvent. The observed molecular weight of phenol will be

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

When $2.44 \ g$ of benzoic acid $(C_6H_5COOH)$ is dissolved in $25 \ g$ of benzene, it shows a depression of freezing point equal to $2.2 \ K$. The molal depression constant of benzene is $5.0 \ K \ kg \ mol^{-1}$. What is the percentage association of the acid, if it forms a dimer in the solution (in $\%$)?