Exothermic
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In thermodynamics, the word exothermic describes a process or reaction that releases energy in the form of heat. Its etymology stems from the Greek prefix ex-, meaning “outside” and the Greek word thermein, meaning “to heat”. The opposite of an exothermic process is an endothermic process, one that absorbs energy in the form of heat.
The concept is frequently applied in physical sciences to e.g. chemical reactions, where chemical bond energy is converted to thermal energy (heat).
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[edit] Overview
Exothermic, also known as exergonic, refers to a transformation in which a system releases heat to the surroundings:
- Q < 0
When the transformation occurs at constant pressure:
- Mixing water and strong acids
- Nuclear fusion
[edit] Implications for chemical reactions
Chemical exothermic reactions are generally more spontaneous than their counterparts, endothermic reactions. In a thermochemical reaction that is exothermic, the heat is placed as a product on the product's side (heat is a product of the reaction).
[edit] See also
[edit] External links
- http://chemistry.about.com/b/a/184556.htm Observe exothermic reactions in a simple experiment
