Which term describes the volume increase that occurs when a liquid material changes to a gas?

The term that accurately describes the volume increase that occurs when a liquid material changes to a gas is known as the expansion ratio. This ratio quantifies how much a certain volume of liquid will expand when it is converted into gas. For many liquids, this expansion can be significant, indicating that a relatively small volume of liquid can result in a much larger volume of vapor.

Understanding the expansion ratio is critical in various applications, such as in the design and operation of equipment that handles gases or when managing hazardous materials. It helps assess how much space will be needed for vapors and informs safety measures in the event of a spill or release.

Vapor pressure refers to the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases at a given temperature, not directly measuring volume change. The compression ratio is a term used mainly in engines and refers to the ratio of the maximum to minimum volume in a cylinder, while density ratio typically measures the mass density of substances rather than changes in volume related to phase changes. Thus, these terms do not describe the volume increase during the phase transition from liquid to gas.