Which term is a colorless, odorless gas occurring as a constituent of natural gas and used as a fuel?

• A. Ethane
• B. Ethyl Chloride
• C. Ethylene glycol
• D. Ethylamine

Answer: (A)

Ethane is the gas that fits this description. It’s a light hydrocarbon (C2H6) that occurs in natural gas, alongside methane, and it can be used as a fuel or as a feedstock in petrochemical processing. It’s colorless and odorless in its pure form, which matches the clue about a colorless, odorless gas. The other options aren’t correct fits: ethyl chloride is not a typical natural gas component and isn’t used as a fuel, ethylene glycol is a liquid antifreeze, and ethylamine is a chemical used in synthesis with a distinct odor, not a natural gas fuel component.