System with Multiple Phases: Heterogeneous Systems

A system in thermodynamics or chemistry refers to a specific part of the universe being studied. A phase is a region within a system where all physical and chemical properties are uniform. Examples include solid, liquid, or gaseous states of matter, or distinct chemical species.

Understanding System Types

• Homogeneous System: A system where properties are uniform throughout. It consists of only one phase (e.g., pure water, a mixture of salt dissolved completely in water).
• Heterogeneous System: A system that contains two or more phases. These phases are physically distinct and separated by boundaries.
• Other system types include Open Systems (exchange matter and energy) and Isolated Systems (exchange neither matter nor energy), but these classifications relate to boundary interactions, not internal composition like phases.

Defining Heterogeneous Systems

The question asks for the term describing a system with more than one phase. Based on the definitions:

• A system with multiple distinct physical regions (phases) is defined as a heterogeneous system.
• Examples include ice floating in water (solid and liquid phases), or oil and water mixture (two immiscible liquid phases).

Therefore, a system consisting of more than one phase is called a heterogeneous system.