What are non-ideal solutions ? Mention the reason for the negative deviation from the Raoult's law.

Explanation

The solutions which do not obey Raoult.s Law over the entire range of concentration and temperature are called as non-ideal solutions.
The reason for the negative deviation from Raoult.s law is that the intermolecular attractive forces between A-A & B-B are weaker than those between A-B and leads to decrease in vapour pressure.