On adding a solute to a solvent having a vapour pressure of $0.80 \ atm$,the vapour pressure reduces to $0.60 \ atm$. The mole fraction of the solute is:

$60 \ g$ of Urea (Mol. wt $60$) was dissolved in $9.9 \ moles$ of water. If the vapour pressure of pure water is $P_o$,the vapour pressure of the solution is: (in $P_o$)

Assume that acetone and water form an ideal solution. If $174 \ g$ of acetone $(CH_3COCH_3)$ is mixed with $126 \ g$ of $H_2O$,what is the vapour pressure of the solution at $298 \ K$? Given that ${P^0}_{acetone} = 360 \ torr$ and ${P^0}_{H_2O} = 24 \ torr$ at $298 \ K$.

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

$100 \, g$ of liquid $A$ (molar mass $140 \, g \, mol^{-1}$) was dissolved in $1000 \, g$ of liquid $B$ (molar mass $180 \, g \, mol^{-1}$). The vapour pressure of pure liquid $B$ was found to be $500 \, torr$. Calculate the vapour pressure of pure liquid $A$ and its vapour pressure in the solution if the total vapour pressure of the solution is $475 \, torr$.

Toluene in the vapour phase is in equilibrium with a solution of benzene and toluene having mole fraction of toluene $0.50$. If vapour pressure of pure benzene is $119 \ torr$ and that of toluene is $37.0 \ torr$ at the same temperature,mole fraction of toluene in vapour phase will be: