Definition

Noun: - Latent heat: The amount of heat energy absorbed or released by a substance during a phase change (such as melting, freezing, vaporization, or condensation) at constant temperature and pressure. This energy is used to alter the molecular structure of the substance rather than change its temperature.

Usage

• This term is used in thermodynamics and physical chemistry to quantify the energy involved in phase transitions.
• It is often specified further as "latent heat of fusion" (for solid-liquid transitions) or "latent heat of vaporization" (for liquid-vapor transitions).

Examples

Advanced Usage

• "Molar heat of transformation": The heat of transformation expressed per mole of substance, rather than per unit mass.
• The concept is crucial in meteorology (e.g., energy transfer in thunderstorms), engineering (e.g., heat exchangers), and materials science (e.g., phase change materials for thermal storage).

Variants and Related Words

• Latent heat: A direct synonym.
• Enthalpy of transformation: A more formal thermodynamic term, often denoted as ΔH.
• Heat of fusion: Specifically for the solid-to-liquid phase change.
• Heat of vaporization: Specifically for the liquid-to-vapor phase change.
• Heat of sublimation: Specifically for the direct solid-to-vapor phase change.

Synonyms

• Latent heat
• Latent enthalpy

Notes

• The "heat of transformation" is a form of latent heat, meaning the energy is "hidden" as it does not cause a temperature change.
• The process occurs at a constant temperature because the energy is used to break or form intermolecular bonds.

Noun

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