Question

A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?​

Answer 1

$\huge \mathcal \blue{ANSWER:}$

2HC ≡ CH + 5O2 → 4CO2 + 2H2O + Heat

When ethyne is burnt in air, it gives a sooty flame. This is due to incomplete combustion caused by limited supply of air. However, if ethyne is burnt with oxygen, it gives a clean flame with temperature 3000°C because of complete combustion. This oxy-acetylene flame is used for welding. It is not possible to attain such a high temperature without mixing oxygen. This is the reason why a mixture of ethyne and air is not used.

$\sf \red{Hope \: its \: help \: you!}$

Answer 2

When ethyne is burnt in air incomplete burning takes place and produce sooty flame due to limited supply oxygen present in the air. However, if ethyne is burnt in oxygen, it gives a clean flame with high temperature (3000°C ) due to complete combustion of ethyne. Hence, This oxy-acetylene flame is used for welding and it is not possible to attain such a high temperature with air. Due this reason a mixture of ethyne and air is not used for welding.