According to Raoult's law,the relative lowering of vapour pressure of a solution of a non-volatile solute is equal to:

The vapour pressure of pure $CCl_4$ (molar mass $= 154 \ g \ mol^{-1}$) and $SnCl_4$ (molar mass $= 170 \ g \ mol^{-1}$) at $25^{\circ} C$ are $115.0 \ torr$ and $238.0 \ torr$ respectively. Assuming ideal behaviour,calculate the total approximate vapour pressure in $torr$ of a solution containing $10 \ g$ of $CCl_4$ and $15 \ g$ of $SnCl_4$.

What is the vapour pressure of a solution containing $1 \ mol$ of a non-volatile solute in $36 \ g$ of water (in $mm \ Hg$)? $(P_1^0 = 400 \ mm \ Hg)$

At $300 \ K$,the vapour pressure of toluene and benzene are $3.63 \ kPa$ and $9.7 \ kPa$ respectively. What is the composition of vapour in equilibrium with the solution containing $0.4$ mole fraction of toluene? (Assume the solution is ideal)

The vapour pressure of pure benzene at a certain temperature is $640 \ mm \ Hg$. $A$ non-volatile non-electrolyte solid weighing $2.175 \ g$ is added to $39.0 \ g$ of benzene. The vapour pressure of the solution is $600 \ mm \ Hg$. What is the molar mass of the solid substance?

Two beakers $A$ and $B$ containing pure water and an aqueous solution,respectively,are placed in a closed container. What will be observed gradually with the passage of time?