Chemistry - Liquid Solution Question with Solution | TestHub

The vapour pressure of pure benzene at a certain temperature is 0.85 bar. Assume hypotheticaly that a non-volatile but electrolyte solid $\left({\mathrm{A}}^{+}{\mathrm{B}}^{-}\right)$weighing 0.5 gm is added to completely dissolve in 39.0 gm of benzene. The vapour pressure of the solution is 0.845 bar. If the solute is $100\%$ dissociated in solution then what is the molar mass of solid substance in $\mathrm{gm}/\mathrm{mol}$ ?