Mixture(s) showing positive deviation from Raoult's law at 35∘C is (are)
Mixture(s) showing positive deviation from Raoult's law at 35∘C is (are)
The correct option is B carbon disulphide + acetone
When intermolecular attraction between two components A and B in the mixture is same as between A and A, or B and B, it is a case of an ideal solution.
When intermolecular attraction between A and B in a mixture is smaller than that between A and A, or B and B, the mixture is more vaporised, b.p is lowered. It is a case of positive deviation from Raoult’s law.
When intermolecular attraction between A and B is higher than that between A and A, or B and B, the mixture is less vaporised, b.p is increased. It is a case of negative deviation.
(a) Methanol molecules CH3OH are hydrogen bonded. In a mixture of CCl4 and CH3OH, the extent of H – bonding is decreased. The mixture is more vaporised thus, positive deviation from Raoult’s law.
(b) Acetone molecules have higher intermolecular attraction due to dipole-dipole interaction. With CS2, this interaction is decreased thus, positive deviation.
(c) A mixture of benzene and toluene forms an ideal solution.
(d) Phenol and aniline have higher interaction due to intermolecular H – bonding. Hence, negative deviation.
When intermolecular attraction between two components A and B in the mixture is same as between A and A, or B and B, it is a case of an ideal solution.
When intermolecular attraction between A and B in a mixture is smaller than that between A and A, or B and B, the mixture is more vaporised, b.p is lowered. It is a case of positive deviation from Raoult’s law.
When intermolecular attraction between A and B is higher than that between A and A, or B and B, the mixture is less vaporised, b.p is increased. It is a case of negative deviation.
(a) Methanol molecules CH3OH are hydrogen bonded. In a mixture of CCl4 and CH3OH, the extent of H – bonding is decreased. The mixture is more vaporised thus, positive deviation from Raoult’s law.
(b) Acetone molecules have higher intermolecular attraction due to dipole-dipole interaction. With CS2, this interaction is decreased thus, positive deviation.
(c) A mixture of benzene and toluene forms an ideal solution.
(d) Phenol and aniline have higher interaction due to intermolecular H – bonding. Hence, negative deviation.
