Question

The gas, which is used for welding purposes is:
A. \[{{C}}{{{H}}_{{4}}}\]
B. \[{{{C}}_{{2}}}{{{H}}_{{6}}}\]
C. \[{{{C}}_{{2}}}{{{H}}_{{4}}}\]
D. \[{{{C}}_{{2}}}{{{H}}_{{2}}}\]

Answer 1

Hint: Welding is a process that joins materials, mainly metals or thermoplastics, by using high temperature to melt the parts together and cooling them thereby causing fusion. Welding is different from processes like brazing and soldering. The gas that can produce very hot flames is used as fuel gas.

Complete step by step answer:
Gas is used in welding for shielding the arc from impurities like air, dust, and other gases. Mostly shielding gases are inert, which makes them suitable for shielding a welding process. They remain stable under extreme conditions. They also provide nurturing to the weld in different ways, depending on the gas being used, including providing more penetration, more fluidity when it is molten, and a smoother surface on the bead.
The gases used for shielding are carbon dioxide, argon, helium, etc and the gases used as fuel are acetylene, propane, butane, etc. The fuel gases along with small amounts of shielding gas mixtures is used in the welding process.
Acetylene is a major fuel gas used in welding and cutting processes. Cutting oxy-fuel or cutting coal is the welding process that uses acetylene. This method is employed for cutting or welding materials that require high temperatures up to \[{{3,500 ^\circ C }}\left( {{{6,330 ^\circ F}}} \right)\]. On comparing all the gases, acetylene can produce the hottest flame.

So, the correct answer is Option D.

Additional Information:
Exposing to large amount of \[{{{C}}_{{2}}}{{{H}}_{{2}}}\] may cause headache, loss of consciousness, and dizziness. If a higher percentage of Ethyne is present in the air, death due to choking can also occur.

Note: Acetylene is the simplest alkyne, \[{{{C}}_{{2}}}{{{H}}_{{2}}}\], it is also known as Ethyne or Vinylene. It is an unsaturated compound with two carbon atoms linked together by a triple bond. It finds application as a chemical building block and as a fuel. It is unstable in its pure form; it is handled as a solution.