The boiling points of $C_6H_6, CH_3OH, C_6H_5NH_2$ and $C_6H_5NO_2$ are $80 \ ^oC, 65 \ ^oC, 184 \ ^oC$ and $212 \ ^oC$ respectively. Which will show the highest vapour pressure at room temperature?

The vapour pressure of pure liquid $A$ is $0.80 \ atm$. On mixing a non-volatile solute $B$ to $A$,its vapour pressure becomes $0.6 \ atm$. The mole fraction of $B$ in the solution is

At room temperature,a dilute solution of urea is prepared by dissolving $0.60 \ g$ of urea in $360 \ g$ of water. If the vapour pressure of pure water at this temperature is $35 \ mm \ Hg$,the lowering of vapour pressure will be: .............. $mm \ Hg$ (molar mass of urea $= 60 \ g \ mol^{-1}$)

$5 \ cm^3$ of acetone is added to $100 \ cm^3$ of water. The vapour pressure of water over the solution:

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 $= 0.02$]

Assertion $:-$ Vapour pressure of a liquid increases on increasing surface area.
Reason $:-$ Rate of vaporisation of a liquid is directly proportional to surface area.