At $298 \ K$,the vapour pressure of pure water is $25 \ torr$. The vapour pressure of water,when $12 \ g$ of urea (molar mass,$60 \ g \ mol^{-1}$) and $36 \ g$ of glucose (molar mass,$180 \ g \ mol^{-1}$) is dissolved in $100 \ g$ of water at the same temperature (in $torr$) is

Which of the following substances,when dissolved in water,causes the maximum decrease in the vapor pressure of water?

At $25\,^{\circ}C$,the vapour pressure of pure liquid $A$ (mol. $wt. = 40$) is $100\, torr$,while that of pure liquid $B$ (mol. $wt. = 80$) is $40\, torr$. The vapour pressure at $25\,^{\circ}C$ of a solution containing $20\, g$ of each $A$ and $B$ is .......... $torr$.

Vapour pressure of solvent is $17.5 \ mm \ Hg$ while that of dilute solution is $17.45 \ mm \ Hg$; the mole fraction of solvent is

At $298 \ K$,vapour pressures of two pure liquids $A$ and $B$ are $200 \ mm \ Hg$ and $400 \ mm \ Hg$ respectively. If mole fractions of $A$ and $B$ in solution are $0.7$ and $0.3$ respectively,what is the mole fraction of $B$ in vapour phase?

$A$ solution containing $30 \,g$ of non-volatile solute in $90 \,g$ of water has a vapour pressure of $2.8 \,kPa$ at $298 \,K$. Further,$18 \,g$ of water is added to the solution and the new vapour pressure becomes $2.9 \,kPa$ at $298 \,K$. Calculate:
$i$. Molar mass of the solute
$ii$. Vapour pressure of water at $298 \,K$