Write a short note on the following .
Pyrolysis

Explanation

Pyrolysis :
Pyrolysis is dened as the thermal decomposition of organic compound into smaller fragments in the absence of air through the application of heat. 'Pyro' means 'fire' and 'lysis' means 'separating'. Pyrolysis of alkanes also named as cracking.
In the absence of air, when alkane vapours are passed through red-hot metal it breaks down into simpler hydrocarbons.
`(1) underset(CH_(3)-CH=CH_(2)+CH_(2)=CH_(2)+H_(2)+CH_(4))underset(darr773K)(CH_(3)-CH_(2)-CH_(3)`
`(2)` `2CH_(3)-CH_(3)overset(773K)(to)CH_(2)=CH_(2)+2CH_(4)`
The products depends upon the nature of alkane, temperature, pressure and presence or absence of catalyst. The ease of cracking in alkanes increases with increase in molecular weight and branching in alkanes. Cracking plays in important role in petroleum industry.