Definition

Noun: * Latent Heat: The thermal energy (heat) absorbed or released by a substance during a change of its physical state (phase change), such as melting, freezing, vaporization, or condensation, while its temperature remains constant. This energy is used to break or form intermolecular bonds rather than to change the temperature.

Usage and Examples

• Latent heat is a key concept in thermodynamics and meteorology.
  • The latent heat released when water vapor condenses into clouds is a major driver of weather systems.
  • When ice melts, it absorbs latent heat from its surroundings, which is why it feels cold.
  • Engineers must account for the latent heat of fusion when designing metal casting processes.

Advanced Usage

• "Latent heat of vaporization": The specific amount of heat required to convert a unit mass of a liquid into a vapor at constant temperature and pressure. It is much larger than the heat of fusion for the same substance.
  • Water has a high latent heat of vaporization, which is why sweating is an effective cooling mechanism for the human body.
• "Latent heat of fusion": The specific amount of heat required to convert a unit mass of a solid into a liquid at its melting point.
  • The latent heat of fusion for ice is used in some cooling applications.

Variants and Related Words

• Sensible Heat: Thermal energy that, when added or removed, results in a temperature change of a substance. This contrasts with latent heat, which does not change the temperature.
• Enthalpy of Phase Change: A more formal thermodynamic term closely related to latent heat.
• Latent (Adjective): Existing but not yet developed, manifest, or active. The term "latent heat" derives from this idea of heat that is "hidden" because it does not show as a temperature change.

Synonyms

• Hidden heat
• Thermal energy of transformation

Related Phrases and Concepts

• Phase Change: The transition of a substance from one state of matter (solid, liquid, gas) to another. Latent heat is the energy associated with this change.
• Constant Temperature Process: A process, like a phase change, that occurs without a change in temperature, during which latent heat is transferred.

Noun

1. heat absorbed or radiated during a change of phase at a constant temperature and pressure