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

At $88 \, ^\circ C$,the vapor pressure of benzene is $900 \, \text{torr}$ and the vapor pressure of toluene is $360 \, \text{torr}$. What is the mole fraction of benzene in the mixture with toluene at $1 \, \text{atm}$ and $88 \, ^\circ C$? Assume benzene and toluene form an ideal solution.

The vapour pressures of chloroform $(CHCl_3)$ and dichloromethane $(CH_2Cl_2)$ at $298 \ K$ are $200 \ mmHg$ and $415 \ mmHg$,respectively. An ideal solution is prepared by mixing $59.75 \ g$ of $CHCl_3$ and $21.25 \ g$ of $CH_2Cl_2$. The mole fractions of chloroform and dichloromethane in the vapour phase,respectively,are:

Formation of a solution from two components can be considered as
$(i)$ Pure solvent $\to$ separated solvent molecules $\Delta H_1$
$(ii)$ Pure solute $\to$ separated solute molecules $\Delta H_2$
$(iii)$ Separated solvent and solute molecules $\to$ solution $\Delta H_3$
Solution so formed will be ideal if

Which condition is not satisfied by an ideal solution?

Which property is shown by an ideal solution?