A carbonaceous fuel (containing no H2 or hydrocarbons) is burnt and the resulting flue gas contains 21% CO2. It means that___________________?

A. 21% excess air has been used for combustion

B. Complete combustion of fuel has taken place

C. 21% excess oxygen has been used for combustion

D. No excess air has been used for combustion

Found an error? Read our corrections policy and submit a sourced correction below. You can also share a useful explanation in your own words.

Discuss the answer or suggest a sourced correction
Thank you for contributing.
Your comment was submitted and will appear after editorial review.

Your email is used only for moderation and is never displayed. Spam, copied material and fabricated endorsements are rejected.