Mass of Urea $(NH_2CONH_2)$ required to be dissolved in $1000 \ g$ of water to reduce the vapour pressure of water by $25 \ \%$ is $...... \ g$. (Nearest integer) Given: Molar mass of $N, C, O$ and $H$ are $14, 12, 16$ and $1 \ g \ mol^{-1}$ respectively.

$A$ solution is prepared by mixing $8.5 \ g$ of $CH_2Cl_2$ and $11.95 \ g$ of $CHCl_3$. If the vapour pressures of pure $CH_2Cl_2$ and $CHCl_3$ at $298 \ K$ are $415 \ mm \ Hg$ and $200 \ mm \ Hg$ respectively,the mole fraction of $CHCl_3$ in the vapour phase is: (Molar mass of $Cl = 35.5 \ g \ mol^{-1}$)

If $Raoult's$ law is obeyed,the vapor pressure of the solvent in a solution is proportional to which of the following?

What is the relationship between vapor pressure and temperature? What will be the vapor pressure at $373 \, K$?

Vapour pressure of water at $293 \, K$ is $17.535 \, mm \, Hg$. Calculate the vapour pressure of water at $293 \, K$ when $25 \, g$ of glucose is dissolved in $450 \, g$ of water.

At $80\,^oC,$ the vapour pressure of pure liquid $'A'$ is $520\, mm\,Hg$ and that of pure liquid $'B'$ is $1000\, mm\,Hg.$ If a mixture solution of $'A'$ and $'B'$ boils at $80\,^oC$ and $1\, atm$ pressure,the amount of $'A'$ in the mixture is ........... $mol$ percent $(1\, atm = 760\, mm\,Hg).$