Determination of the molar mass of acetic acid in benzene using freezing point depression is affected by

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?

If $0.15 \ m$ aqueous solution of $KCl$ freezes at $-0.51^{\circ} C$,calculate the van't Hoff factor of $KCl$ (cryoscopic constant of water is $1.86 \ K \ kg \ mol^{-1}$).

If the degree of association is $70 \%$ for the reaction $2 A \rightleftharpoons (A)_2$, the van't-Hoff factor for the solute $A$ is

Assertion : The molecular weight of acetic acid determined by depression in freezing point method in benzene and water was found to be different.
Reason : Water is polar and benzene is nonpolar.

The van't Hoff factor $(i)$ is .....