Which of the following liquid pairs shows a positive deviation from Raoults law?
Which of the following liquid pairs shows a positive deviation from Raoults law?
The correct option is C Benzene methanol
Positive deviation indicates weaker intermolecular forces of attractions between different components in the mixture than attractions in the pure individual components. Due to weakened forces of attractions, the escaping tendency of the liquids in the mixture will be more than expected i.e., the vapor pressure of the mixture is greater than expected. In all of the above mixtures, except Benzene - methanol, the total vapor pressure of the mixture is less than expected i.e., show negative deviation, since the attraction forces are stronger when compared to those in pure liquids. The weaker forces of attraction are replaced by stronger forces of attraction.However, in Benzene - methanol mixture the intermolecular forces of attractions are weaker than those in pure liquids. Hence this mixture shows positive deviation.
Positive deviation indicates weaker intermolecular forces of attractions between different components in the mixture than attractions in the pure individual components. Due to weakened forces of attractions, the escaping tendency of the liquids in the mixture will be more than expected i.e., the vapor pressure of the mixture is greater than expected. In all of the above mixtures, except Benzene - methanol, the total vapor pressure of the mixture is less than expected i.e., show negative deviation, since the attraction forces are stronger when compared to those in pure liquids. The weaker forces of attraction are replaced by stronger forces of attraction.However, in Benzene - methanol mixture the intermolecular forces of attractions are weaker than those in pure liquids. Hence this mixture shows positive deviation.
