Editing Calorie (section)

===Chemistry and physics===
In other scientific contexts, the term "calorie" and the symbol "cal" almost always refers to the small unit; the "large" unit being generally called "kilocalorie" with symbol "kcal". It is mostly used to express the amount of energy released in a [[chemical reaction]] or [[Phase transition|phase change]], typically per [[mole (unit)|mole]] of substance, as in [[kilocalorie per mole|kilocalories per mole]].<ref name=rappo2007/> It is also occasionally used to specify other energy quantities that relate to reaction energy, such as [[bond energy|enthalpy of formation]] and the size of [[activation energy|activation barrier]]s.<ref name=bhag2002/> However, it is increasingly being superseded by the SI unit, the joule (J); and metric multiples thereof, such as the kilojoule (kJ).{{citation needed|date=March 2023}}

The lingering use in chemistry is largely because the energy released by a reaction in [[aqueous solution]], expressed in kilocalories per mole of reagent, is numerically close to the concentration of the reagent in moles per [[liter]] multiplied by the change in the temperature of the solution in kelvins or degrees Celsius. However, this estimate assumes that the [[volumetric heat capacity]] of the solution is 1&nbsp;kcal/([[litre|L]]⋅[[kelvin|K]]), which is not exact even for pure water.{{citation needed|date=March 2023}}