Question

A mixture of oxygen and ethane is burned for welding. Can you tell why mixture of ethane and air is not used?

Answer 1

The required is:

$2CH=CH+5O_2\to 4CO+2H_{2}O$ + heat

Now,

We can easily explain that when ethyne is brunt in air, it gives a sooty flame.

This is due to incomplete combustion caused by limited supply of air.

Similar,

When ethyne is burnt with oxygen, it gives a clean flame due to complete combustion.

This oxy-acetylene flame is used for welding.

So,

It is not possible to attain such a high temperature without mixing of oxygen.

This is the required reason.