Question

What happens when methane is burned in insufficient amount of air?

Answer 1

This reaction depends upon the amount of oxygen:
(a) When methane burnt in air or oxygen, it produces large amounts of heat, together with carbon and water vapour formation. Hence it is used as fuels. Combustion of methane can explained by following reaction :
$\underset{Methane}{C{H}_4\left(g\right)+}\underset{\left(fromair\right)}{\underset{oxygen}{O_2\left(g\right)}}\stackrel{\Delta }{\to }\underset{dioxide}{\underset{Carbon}{C{O}_2\left(g\right)}}+\underset{Water}{2H_{2}O}\left(vap\right)+Heat$
(b) When methane burnt in a very limited supply of air, it gives carbon black
$C{H}_{4+}\underset{\left(verylimited\right)}{\underset{Air}{O_2}}\to \underset{Carbonblack}{C}+2H_{2}O$