1. There is no change in volume on mixing two components (solute and solvent) ∆Vmixing = 0
2. There is no exchange of heat when the solute is dissolved in solvent (∆Hmixing = 0)
3. Escaping tendency of the solute and the solvent present in it should be same as in pure liquids.
4. Examples, For ideal solution: Benzene and toluene, n-Hexane and n-Heptane, ethyl bromide and ethyl iodide, chlorobenzene and bromo benzene.
