azeotrópia

Azeotropia refers to a phenomenon in which a mixture of two or more substances exhibits a constant boiling point. This occurs when the vapor pressure of the mixture is equal to the vapor pressure of the pure components at the same temperature. When an azeotrope boils, the composition of the liquid and the vapor are identical, meaning that distillation cannot be used to separate the components further.

There are two types of azeotropes: minimum boiling azeotropes and maximum boiling azeotropes. A minimum boiling azeotrope boils at a temperature lower than either of the pure components, while a maximum boiling azeotrope boils at a temperature higher than either of the pure components. The formation of azeotropes is a result of intermolecular forces between the components in the mixture. Deviations from ideal behavior, such as strong attractive or repulsive forces, can lead to azeotrope formation.

Azeotropic distillation is a technique used to overcome the limitations of azeotropes. This often involves adding a third component, known as an entrainer, which forms a new, lower-boiling azeotrope with one of the original components, allowing for its removal. Understanding azeotropia is crucial in various chemical processes, including distillation, solvent recovery, and the purification of mixtures.