Question

The decomposition of a compound by heat in the absence of air is called __.

Answer 1

The decomposition of a compound by heat in the absence of air is called pyrolysis. When pyrolysis occurs in alkanes, the process is termed as cracking. The alkanes on heating under high temperature or in the presence of a catalyst in the absence of air, are broken down into lower alkanes, alkenes and hydrogen.

$2C{H}_4\stackrel{{1500}^{0}C}{\to }HC\equiv CH+3H_2$