The vapor pressure of water at a certain temperature is $3000 \ N \ m^{-2}$. When a non-electrolyte solute is added,it decreases by $300 \ N \ m^{-2}$. The molality of the solution is ............. $m$.

The vapour pressure of a solvent decreases by $2.5 \ mm \ Hg$ by adding a solute. What is the mole fraction of solute? (Vapour pressure of pure solvent is $250 \ mm \ Hg$)

The vapor pressures of two pure liquids $(A)$ and $(B)$ are $100 \ Torr$ and $80 \ Torr$ respectively. What is the total vapor pressure of the solution formed by mixing $2 \ moles$ of $(A)$ and $3 \ moles$ of $(B)$ (in $Torr$)?

The relative lowering in vapour pressure of an aqueous solution of urea which is $6 \%$ by weight,is

One mole of a non-volatile solute is dissolved in two moles of water. What is the vapor pressure of this solution relative to that of pure water?

Calculate the amount of solute dissolved in $612 \ g$ of water at $30^{\circ} C$ if molar mass of solute is $342 \ g \ mol^{-1}$ (Relative vapour pressure lowering is $0.025$ and molar mass of water $18 \ g \ mol^{-1}$ ). (in $g$)