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When a solution shows positive deviation from Raoult's law, the intermolecular forces present are weaker than those present in the ideal solution. The total vapour pressure of the solution is greater than the total vapour pressure of the ideal solution.

Also, the vapour pressure of each component is greater than that predicted from Raoult's law. Hence, the azeotropic mixture of two liquids boils at a lower temperature than either of them.