The vapour pressure of pure benzene at a certain temperature is $200 \ mm \ Hg$. At the same temperature,the vapour pressure of a solution containing $2 \ g$ of a non-volatile,non-electrolyte solid in $78 \ g$ of benzene is $195 \ mm \ Hg$. What is the molecular weight of the solid?

The mass of non-volatile,non-electrolyte solute (molar mass $= 50 \ g \ mol^{-1}$) needed to be dissolved in $114 \ g$ octane to reduce its vapour pressure to $75\%$ is .............. $g$.

Vapour pressure of a pure solvent is $550 \ mm$ of $Hg$. By addition of a non-volatile solute,it decreases to $510 \ mm$ of $Hg$. Calculate the mole fraction of the solute in the solution.

$3 \ g$ of urea is dissolved in $45 \ g$ of water. The relative lowering of vapour pressure is

Select the correct option using $T$ (True) or $F$ (False) for the following statements: $(1)$ The decrease in vapour pressure is equal to the mole fraction of the solute. $(2)$ The relative lowering of vapour pressure is directly proportional to the amount of solute. $(3)$ The relative lowering of vapour pressure is equal to the mole fraction of the solute. $(4)$ The vapour pressure of the solution is equal to the mole fraction of the solvent.

Two open beakers,one containing a solvent and the other containing a mixture of that solvent with a non-volatile solute,are together sealed in a container. Over time: