Editing Standard enthalpy of reaction (section)

== Subcategories ==
In each case the word ''standard'' implies that all reactants and products are in their [[standard state]]s.
* [[Heat of combustion|Standard enthalpy of combustion]] is the enthalpy change when one mole of an organic compound reacts with molecular [[oxygen]] (O<sub>2</sub>) to form carbon dioxide and liquid water. For example, the standard enthalpy of combustion of [[ethane]] gas refers to the reaction C<sub>2</sub>H<sub>6</sub> (g) + (7/2) O<sub>2</sub> (g) → 2 CO<sub>2</sub> (g) + 3 H<sub>2</sub>O (l).
* [[Heat of formation|Standard enthalpy of formation]] is the enthalpy change when one mole of any compound is formed from its constituent elements in their standard states. The enthalpy of formation of one mole of ethane gas refers to the reaction 2 C (graphite) + 3 H<sub>2</sub> (g) → C<sub>2</sub>H<sub>6</sub> (g).
* Standard enthalpy of [[hydrogenation]] is defined as the enthalpy change observed when one mole of an [[Saturated and unsaturated compounds|unsaturated]] compound reacts with an excess of hydrogen to become fully saturated. The hydrogenation of one mole of [[acetylene]] yields ethane as a product and is described by the equation C<sub>2</sub>H<sub>2</sub> (g) + 2 H<sub>2</sub> (g) → C<sub>2</sub>H<sub>6</sub> (g).
* [[Standard enthalpy of neutralization]] is the change in enthalpy that occurs when an acid and base undergo a neutralization reaction to form one mole of water. For example in [[aqueous solution]], the standard enthalpy of neutralization of [[hydrochloric acid]] and the base [[magnesium hydroxide]] refers to the reaction HCl (aq) + 1/2 Mg(OH)<sub>2</sub> → 1/2 MgCl<sub>2</sub> (aq) + H<sub>2</sub>O(l).