Which property is shown by an ideal solution?

$A$ liquid mixture contains $10 \ moles$ of $A$ $(P_A^0 = 200 \ mm \ Hg)$ and $10 \ moles$ of $B$ $(P_B^0 = 100 \ mm \ Hg)$. The vapour pressure over the liquid mixture is $160 \ mm \ Hg$. Which statement is correct?

For which of the following mixtures is $\Delta_{mix} H > 0$?

At $27^o C$,the vapor pressure of pure liquid $A$ is $70 \ torr$. It forms an ideal solution with $B$. The mole fraction of $B$ is $0.2$ and the vapor pressure of the solution at $27^o C$ is $84 \ torr$. What is the vapor pressure of pure liquid $B$ at $27^o C$ (in $torr$)?

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 $1000 \ torr$. Use the provided vapor pressure vs. temperature graph to find the answer. (in $^{\circ}C$)

Two liquids $A$ and $B$ have vapour pressure in the ratio $P_A^o : P_B^o = 1 : 3$ at a certain temperature. Assume $A$ and $B$ form an ideal solution and the ratio of mole fractions of $A$ to $B$ in the vapour phase is $4 : 3$. Then the mole fraction of $B$ in the solution at the same temperature is