The observed molar mass determined for $Na_2SO_4$ by the freezing point depression method is $50.0 \ g/mol$. The theoretical molar mass of $Na_2SO_4$ is $142 \ g/mol$. What will be the degree of dissociation $\alpha$ for $Na_2SO_4$ in water?

If a solute associates in a solvent,its experimentally calculated molar mass using the boiling point elevation method will be

In a solution of sulfur in carbon disulfide,$80 \%$ of the sulfur exists as $S_8$ and the remaining exists as $S_2$. The van't Hoff factor '$i$' will be:

The observed and calculated molecular mass of silver nitrate $(AgNO_3)$ are $92.64$ and $170$ respectively. The degree of dissociation of silver nitrate is ........ $\%$.

The van't Hoff factor $(i)$ 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 $\%$)?