Question

A mixture of oxygen and ethyne is burnt for welding. Why a mixture of ethyne and air is not used?

• A. ethene can not burn in air
• B. incomplete combustion takes place
• C. ethene burn in air with explosion
• D. none of these

Answer 1

The correct option is B incomplete combustion takes place

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.