i. Ethyne is an unsaturated hydrocarbon. On combustion in air, it produces a yellow flame with lots of black smoke.
ii. Due to this incomplete combustion, heat produced is low and temperature obtained is also low.
iii. For welding purposes,high temperature is required.
iv. When a mixture of ethyne and oxygen is used, complete combustion is achieved and very high temperature required for welding is obtained. Hence, a mixture of ethyne and oxygen is used for welding instead of a mixture of ethyne and air.
