What is the gas allowed as a fuel in the example?

What is the gas allowed as a fuel in the example?

• A. Propane
• B. Oxygen
• C. Nitrogen
• D. Argon

Answer: (A)

The main idea here is identifying which gas can supply energy through combustion. A fuel gas provides chemical energy that burns with an oxidizer to produce heat. Propane is a hydrocarbon fuel that readily combusts when mixed with air or with an oxidizer, delivering usable heat in flames, torches, and many gas-fueled appliances. Oxygen, while essential to support combustion, is not a fuel itself—it’s the substance that reacts with the fuel. Nitrogen is largely inert and serves as a diluent or purge gas, not a source of energy. Argon is an inert shielding gas used to protect the weld or flame from air, not to fuel combustion. So propane is the gas that serves as the fuel in the example.

The main idea here is identifying which gas can supply energy through combustion. A fuel gas provides chemical energy that burns with an oxidizer to produce heat.

Propane is a hydrocarbon fuel that readily combusts when mixed with air or with an oxidizer, delivering usable heat in flames, torches, and many gas-fueled appliances. Oxygen, while essential to support combustion, is not a fuel itself—it’s the substance that reacts with the fuel. Nitrogen is largely inert and serves as a diluent or purge gas, not a source of energy. Argon is an inert shielding gas used to protect the weld or flame from air, not to fuel combustion.

So propane is the gas that serves as the fuel in the example.