Question

Question 2
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

When a mixture of oxygen and ethyne is burnt, it gives a clean flame with high temperature due to complete combustion of ethyne. But when ethyne is burnt with air, it results in incomplete combustion. Incomplete combustion will not give a high temperature. The flame obtained in this case is sooty. This is the reason why oxygen is used instead of air to burn ethyne.