In a solution,the mole ratio of pentane $(A)$ and hexane $(B)$ is $1:4$. At $20^o C$,the vapor pressures of these pure hydrocarbons are $440 \ mm$ and $120 \ mm$ respectively. The mole fraction of pentane in the vapor phase is.....

Explain the vapour pressure of solutions of solids in liquids.

How many grams of glucose are required to prepare an aqueous solution of glucose having a vapor pressure of $23.324 \ mm \ Hg$ at $25^{\circ} C$ in $100 \ g$ of water? The vapor pressure of pure water at $25^{\circ} C$ is $23.8 \ mm \ Hg$.

The vapour pressure of a solvent decreases by $20 \ mm$ of $Hg$ when a non-volatile solute is added to the solvent. The mole fraction of the solute in the solution is $0.5$. What should be the mole fraction of the solvent for the decrease in the vapour pressure to be $10 \ mm$ of $Hg$?

Which of the following changes will cause an increase in the vapour pressure of a $1 \ m$ aqueous $KI$ solution at the same temperature?

Find the molar mass of a nonvolatile solute when $20 \ g$ of it is dissolved in $200 \ g$ of water at $300 \ K$. [Relative lowering of vapour pressure $= 0.02$]