During the determination of the molar mass of benzoic acid in benzene using the freezing point depression method,it corresponds to which of the following?

Assertion : Molecular mass of benzoic acid when determined by colligative properties is found high.
Reason : Dimerisation of benzoic acid.

$1.7920 \ g$ of $K_2SO_4$ is present in $1000 \ mL$ of solution. If such solution has an osmotic pressure of $0.680 \ bar$ at $26 \ ^\circ C$,then find out the van't Hoff factor value.

The molecular weight of benzoic acid dissolved in benzene is found to be ............ $g/mol$.

$2$ molal solution of a weak acid $HA$ has a freezing point of $-3.885^{\circ} C$. The degree of dissociation of this acid is ........ $\times 10^{-3}$. (Round off to the Nearest Integer).
[Given: Molal depression constant of water = $1.85 \ K \ kg \ mol^{-1}$,Freezing point of pure water = $0^{\circ} C$]

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