Question

Distillation of mixtures of ethanol and water cannot increase the ethanol content of the mixture above 95% because this solution boils at a lower temperature than either pure ethanol or pure water. The term which describes this lower boiling mixture is ________.

Answer 1

Explanation:

Azeotrope is defined as a mixture consisting of two liquids which has constant boiling point and a constant composition throughout the distillation.

For example, the boiling point of water is $100^{o}C$ and the boiling point of ethanol is $78.3^{o}C$. So, a mixture of ethanol and water will act as a binary azeotrope as there are two components.

As the boiling point of this mixture is below the boiling point of either of the two components then it is also a minimum boiling azeotrope.

Thus, we can conclude that distillation of mixtures of ethanol and water cannot increase the ethanol content of the mixture above 95% because this solution boils at a lower temperature than either pure ethanol or pure water. The term which describes this lower boiling mixture is azeotrope.