Chloroform-benzene mixture shows negative deviation from Rault's law. This is because when these liquids are mixed, hydrogen bonding takes places between the H-atom of chloroform and the π-electron cloud of the benzenering. Due to this the escaping tendency of either of the liquid moleculers disminishes. As the
A - B > > A - A or B - B
the mixture shows negative deviation from Rault's law.
