Ideal & Non Ideal Solutions:
#) Ideal Solutions: The concept of an ideal solution is fundamental to chemical thermodynamics and its applications, such as the use of colligative properties.
*) An ideal solution or ideal mixture is a solution in which the enthalpy of solution (ΔHsolution=0) is zero; with the closer to zero the enthalpy of solution, the more “ideal” the behavior of the solution becomes.
*) Since the enthalpy of mixing (solution) is zero, the change in Gibbs energy on mixing is determined solely by the entropy of mixing
#) Non-ideal Solutions: A non-ideal solution is a solution that does not abide to the rules of an ideal solution where the interactions between the molecules are identical (or very close) to the interactions between molecules of different components.
*) That is, there is no forces acting between the components: no Van-der-Waals nor any Coulomb forces. We assume ideal properties for dilute solutions.