section_path: Reaction types/Combustion
section_name: Combustion
paragraph_text: Combustion
  
  In a combustion reaction, an element or compound reacts with an oxidant, usually oxygen, often producing energy in the form of heat or light. Combustion reactions frequently involve a hydrocarbon. For instance, the combustion of 1 mole (114 g) of octane in oxygen C 8 H 18 (l) + 25 2 O 2 (g) ⟶ 8 CO 2 + 9 H 2 O (l) {\displaystyle {\ce {C8H18(l) + 25/2 O2(g)->8CO2 + 9H2O(l)}}}
  
  releases 5500 kJ. A combustion reaction can also result from carbon, magnesium or sulfur reacting with oxygen. 2 Mg (s) + O 2 ⟶ 2 MgO (s) {\displaystyle {\ce {2Mg(s) + O2->2MgO(s)}}} S (s) + O 2 (g) ⟶ SO 2 (g) {\displaystyle {\ce {S(s) + O2(g)->SO2(g)}}}