A phase change can transfer heat without changing temperature.
Difficulty
Beginner
Read time
5 min
Prerequisites
Basic algebra and consistent SI units
Source
OpenStax, College Physics 2e, §14.3 (Paul Peter Urone and Roger Hinrichs)Textbook reference retained from the OpenFormulaGraph dataset; adaptation credits and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted the notation, explanations, assumptions, and topic placement, and expanded the numerical check into a worked example. The textbook section link was corrected.
A phase change can transfer heat without changing temperature. The latent heat gives the energy per unit mass for the stated transition. The sign of heat transfer depends on whether energy enters or leaves the substance.
| Symbol | Meaning | Units |
|---|---|---|
| Magnitude of phase-change heat | ||
| Mass changing phase | ||
| Specific latent heat |
Estimate the heat needed for a phase change.
Compare energy absorbed during melting with sensible heating.
Find the heat absorbed to melt 0.500 kg of ice already at its melting temperature, using latent heat of fusion 334000 J/kg.
Textbook reference retained from the OpenFormulaGraph dataset; adaptation credits and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted the notation, explanations, assumptions, and topic placement, and expanded the numerical check into a worked example. The textbook section link was corrected.
Assumptions
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