General Knowledge - General Science - Discussion

In welding we use oxygen and acetylene because acetylene provides a comparatively higher temperature.

What is acetylene?

Acetylene is a alkynne (CH-=CH). It is a gas.

It is also called as oxyacetylene gas and has ability to create very high temperature.

Oxy-fuel welding (commonly called oxyacetylene welding, oxy welding, or gas welding in the U.S.) and oxy-fuel cutting are processes that use fuel gases and oxygen to weld and cut metals, respectively. French engineers Edmond Fouché and Charles Picard became the first to develop oxygen-acetylene welding in 1903. Pure oxygen, instead of air (20% oxygen/80% nitrogen), is used to increase the flame temperature to allow localized melting of the workpiece material (e.g. steel) in a room environment. A common propane/air flame burns at about 3,630 °F (2,000 °C), a propane/oxygen flame burns at about 4,530 °F (2,500 °C), and an acetylene/oxygen flame burns at about 6,330 °F (3,500 °C).

Its oxyacetylene gas which melts metals like iron steel etc. So right answer is option D.

For welding of metals such as Mg, Al inert atmosphere is necesarry To create this argon, neon also used.

Argon is also widely used for welding.

oxygen react with acetylene form oxy acetylene which produces a very high temperature

Bcoz, acetylene burns in oxygen gas producing oxy-acetylene flame which has temp above 3000 degrees. So it is used for welding.