Which condition is not satisfied by an ideal solution?

We know that the ideal solution can be formed in accordance with the Raoult's law.

Now, according to this law, the change in enthalpy of the reaction and change in the volume of the reaction before and after mixing should be equal to zero for ideal gas.

Entropy of mixture always positive for mixing of two or more solutions.

Thus, for ideal solution

${∆}_{\mathrm{mix}}\mathrm{H} = 0$ and ${∆}_{\mathrm{mix}}\mathrm{S} > 0$