Question

For a non-ideal solution showing positive deviation from Raoult’s law, `Delta H_"mixing"` is ______.

Answer 1

For a non-ideal solution showing positive deviation from Raoult’s law, `Delta H_"mixing"` is positive.

Explanation:

A non-ideal solution shows positive deviation from Raoult’s Law when the A-B intermolecular forces are weaker than A-A and B-B. This makes it easier for molecules to escape into the vapour phase, increasing vapour pressure. Weaker interactions mean energy is absorbed during mixing. So, `Delta H_"mixing" > 0`.