Types of Flames II

Most recent answer: 10/22/2007

Q:
We know that the non-luminous uses carbon dioxide to burn, so what does it give out?
- PangJiingHuey (age 13)
Anglican High, Singapore
A:
Pang -

There is no such thing as a flame that burns up CO2. CO2 is the most ’burnt up’ form that a carbon-based molecule can end up in. The scientific way of saying this is that it is the most ’oxidized’ form possible. Flames work by converting molecules with carbon in them into CO2 and other molecules.

If it doesn’t have enough oxygen, a flame might not be able to turn the molecule all the way into CO2 - sometimes it produces what we call ’intermediates’, or molecules that are more burnt up than they used to be, but less burnt up than CO2 (like the molecules in soot). Luminous flames are less efficient than non-luminous ones, so they are more likely to produce these intermediates. But no flame can burn up CO2.

-Tamara

(published on 10/22/2007)