The vapour pressures of two liquids $A$ and $B$ in their pure states are in the ratio of $1:2$. $A$ binary solution of $A$ and $B$ contains $A$ and $B$ in the mole proportion of $1:2$. The mole fraction of $A$ in the vapour phase of the solution will be

The vapour pressure of ethanol $(C_2H_5OH)$ and methanol $(CH_3OH)$ at $298 \ K$ is $44.5 \ mm \ Hg$ and $88.7 \ mm \ Hg$ respectively. At the same temperature,an ideal solution is prepared by mixing $60 \ g$ of ethanol and $40 \ g$ of methanol. Find the mole fraction of methanol in the vapour state.

Vapour pressure of chloroform $(CHCl_{3})$ and dichloromethane $(CH_{2}Cl_{2})$ at $298\,K$ are $200\,mm\,Hg$ and $415\,mm\,Hg$ respectively. $(i)$ Calculate the vapour pressure of the solution prepared by mixing $25.5\,g$ of $CHCl_{3}$ and $40\,g$ of $CH_{2}Cl_{2}$ at $298\,K$ and,$(ii)$ mole fractions of each component in vapour phase.

The vapour pressure of water is $12.3 \, kPa$ at $300 \, K$. Calculate the vapour pressure of a $1 \, molal$ solution of a non-volatile solute in it.

The vapour pressure of a solvent $A$ is $0.80 \, atm$. When a non-volatile substance $B$ is added to this solvent its vapour pressure drops to $0.6 \, atm$. What is the mole fraction of $B$ in the solution?

Which solution has the lowest vapor pressure?