Assuming ideal behaviour,the enthalpy and volume of mixing of two liquids respectively,are

Which of the following will form an ideal solution?

The total pressure observed by mixing two liquids $A$ and $B$ is $350 \ mm \ Hg$ when their mole fractions are $0.7$ and $0.3$ respectively. The total pressure becomes $410 \ mm \ Hg$ if the mole fractions are changed to $0.2$ and $0.8$ respectively for $A$ and $B$. The vapour pressure of pure $A$ is $........... \ mm \ Hg$. (Nearest integer)
Consider the liquids and solutions behave ideally.

$A$ binary liquid solution is prepared by mixing $n$-heptane and ethanol. Which one of the following statements is correct regarding the behaviour of the solution?

In a binary ideal solution of liquids $A$ and $B$ at a constant temperature,the mole fraction of $B$ in the liquid phase is $0.4$ and in the vapor phase is $0.25$. If $P_B^o = 40 \ mm \ Hg$,then the vapor pressure of pure liquid $A$ at that temperature is .......... $mm \ Hg$.

Assuming the formation of an ideal solution,determine the boiling point of a mixture containing $1560 \ g$ benzene (molar mass $= 78 \ g/mol$) and $1125 \ g$ chlorobenzene (molar mass $= 112.5 \ g/mol$) against an external pressure of $1000 \ torr$ using the provided graph. (in $^{\circ}C$)