Which shielding gas can break down in the arc to form carbon monoxide?

Which shielding gas can break down in the arc to form carbon monoxide?

• A. CO2
• B. Argon
• C. Helium
• D. Nitrogen

Answer: (A)

The arc’s extreme heat can break down certain shielding gas molecules, so some gases actively participate in arc chemistry rather than just shielding. Among the options, carbon dioxide is the one that can split into carbon monoxide and oxygen in the arc. The high temperature provides enough energy to dissociate CO2, so CO forms in the arc region. In contrast, argon and helium are inert noble gases that don’t readily dissociate or react under welding arc conditions, and nitrogen, while it can participate in some reactions, does not typically break down to form carbon monoxide in this context. So CO2 is the shielding gas that can break down to form carbon monoxide.

The arc’s extreme heat can break down certain shielding gas molecules, so some gases actively participate in arc chemistry rather than just shielding. Among the options, carbon dioxide is the one that can split into carbon monoxide and oxygen in the arc. The high temperature provides enough energy to dissociate CO2, so CO forms in the arc region. In contrast, argon and helium are inert noble gases that don’t readily dissociate or react under welding arc conditions, and nitrogen, while it can participate in some reactions, does not typically break down to form carbon monoxide in this context. So CO2 is the shielding gas that can break down to form carbon monoxide.