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

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.

Answer 2

Answer:

• A mixture of oxygen and ethyne is burnt for welding instead of mixture of ethyne and air because the production of heat is very important for welding metals.
• When oxygen and ethyne are burnt, it burns completely and produces a higher temperature than air and ethyne.
• Oxygen and ethyne produce very hot blue flame but the mixture of air and ethyne gives out a sooty flame which means that there are unburnt particles resulting in lesser heat.