The vapour pressure of a liquid depends on

Which of the following can be measured by the Ostwald-Walker dynamic method?

Vapour pressure of a solution is

Dry air is passed through a solution containing $10 \ g$ of solute in $90 \ g$ of water and then through pure water. The loss in weight of the solution is $2.5 \ g$ and the loss in weight of the solvent is $0.05 \ g$. The molecular weight of the solute is:

Two $5 \ molal$ solutions are prepared by dissolving a non-electrolyte,non-volatile solute separately in the solvents $X$ and $Y$. The molecular weights of the solvents are $M_X$ and $M_Y$,respectively,where $M_X = \frac{3}{4} M_Y$. The relative lowering of vapour pressure of the solution in $X$ is $m$ times that of the solution in $Y$. Given that the number of moles of solute is very small in comparison to that of solvent,the value of $m$ is

The vapour pressure of acetone $(CH_3COCH_3)$ at $20\,^{\circ}C$ is $185\, torr$. When $1.2\, g$ of a non-volatile substance was dissolved in $100\, g$ of acetone at $20\,^{\circ}C$,its vapour pressure was $183\, torr$. The molar mass $(g\, mol^{-1})$ of the substance is