What happens to the state of a zeotropic mixture during evaporation?

When a zeotropic mixture undergoes evaporation, it separates into individual components. A zeotropic mixture contains two or more refrigerants that have different boiling points. As the mixture is heated, the component with the lower boiling point evaporates first, leaving behind a larger proportion of the remaining liquid components.

This process highlights a key characteristic of zeotropic mixtures: the non-constant composition during phase change. Unlike azeotropic mixtures, which maintain a consistent ratio of components throughout phase change, zeotropic mixtures do not retain their original ratio of composition, leading to distinct evaporating components.

The significance of this behavior is crucial for applications in refrigeration and HVAC systems, as it impacts the efficiency and performance of the refrigeration cycle, requiring careful consideration in the design and operation of systems utilizing zeotropic refrigerants.