An aqueous solution of hydrochloric acid:

$A$ mixture of methanol $(MeOH)$ and ethanol $(EtOH)$ forms an ideal solution. If the partial pressures of methanol and ethanol are $2.619 \ kPa$ and $4.556 \ kPa$ respectively,what will be the mole fractions of the components in the vapor phase?

$A$ mixture of phenol and aniline shows negative deviation from Raoult's law. This is due to the formation of

Two liquids $x$ and $y$ form an ideal solution. At $300 \ K$,the vapor pressure of a solution containing $1 \ mol$ of $x$ and $3 \ mol$ of $y$ is $550 \ mm \ Hg$. At the same temperature,if $1 \ mol$ of $y$ is added to the solution,the vapor pressure increases by $10 \ mm \ Hg$. The vapor pressures of pure $x$ and $y$ are respectively:

At $20^o C$,benzene and toluene form an ideal solution. The pure vapor pressure of benzene is $75 \ torr$ and that of toluene is $22 \ torr$. What is the partial vapor pressure of benzene in a solution containing $78 \ g$ of benzene and $46 \ g$ of toluene at $20^o C$?

What is vapour pressure? And what is an ideal solution?