Describe the combustion reactions of carbon and its compounds.

Carbon, its allotropic forms and compounds burn in sufficient oxygen to give carbon dioxide and water, with the liberation of large amount of heat and light.

(i)    C + O₂ → CO₂ + heat + light
(ii)    CH₄ + 2O₂→ CO₂ + 2H₂O+ heat + light
(iii)    CH₃CH₂OH + 3O₂→ 2CO₂ + 3H₂O+ heat + light

If carbon or its compound are burnt in an insufficient supply of air, then incomplete combustion of carbon or its compound takes place and carbon monoxide and water vapour and some heat are produced.

$2{\mathrm{C}}_4{\mathrm{H}}_{10}+9{\mathrm{O}}_2 \underset{\mathrm{Combustion}}{\overset{\mathrm{Incomplete} }{\to }} 8\mathrm{CO}\left(\mathrm{g}\right) + 10{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right) + \mathrm{heat}$