Question

thermal decomposition of alkanes in the absence of air is called

Answer 1

I think it's alkaline fluid

Answer 2

The answer is cracking.

The thermal decomposition of alkanes in the absence of air is called cracking.

The process of decomposition of a compound by heat in the absence of air is known as pyrolysis. When this reaction takes place in alkanes, it is referred to as cracking. A catalyst is used in this reaction and the alkanes get broken down to alkenes, lower alkanes and hydrogen.