What is meant by positive from Raoul's Law ? Give an example an example. What is the sing of `DeltaH_(mix)` for positive deviation ?

Explanation

When the vapor pressure of a solution is higher than the predicted value by Raoult’s law, it is called positive deviation’. In such cases intermolecular interactions between solute and solvent particles (A and B) are weaker than those between solute-solute (A – A) and solvent-solvent (B – B).
Examples of solutions showing positive deviation:
(i) Ethyl alcohol and water (ii) Acetone and carbon disulphide