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Hess's law
Sign in to saveAlso known as Hess's law of constant heat summation
relationship in physical chemistry
Hess's law states that the total amount of heat released or absorbed in a chemical reaction depends only on the starting and ending substances, not on the path the reaction takes to get there. This principle is useful for calculating the heat energy of reactions that are difficult to measure directly by combining measurements from other related reactions.
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Wikidata facts
- Instance of
- physical law
- Named after
- Germain Henri Hess
Show 3 more facts
- time of discovery or invention
- 1840-00-00
- discoverer or inventor
- Germain Henri Hess
- Commons category
- Hess cycles
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Encyclopedic overview
A representation of Hess's law (where H represents enthalpy)
In physical chemistry and thermodynamics, Hess's law of constant heat summation, also known simply as Hess's law, is a scientific law named after Germain Hess, a Swiss-born Russian chemist and physician who published it in 1840. The law states that the total enthalpy change during the complete course of a chemical reaction is independent of the sequence of steps taken.
Excerpted from Wikipedia’s “Hess's law” article, available under the CC BY-SA 4.0 licence.