Cecil's Definition of Fire Is Partly Wrong

In the article What exactly is fire? Cecil states in his definition that oxygen is required to produce a flame. This is not true. In most typical flames, oxygen serves as the oxidizer for the fuel. An exception to this arrives, however, when chlorine is used to combust with hydrogen to produce hydrogen chloride (HCL). This reaction produces a flame as well.


Fluorine works even better. In fact, you can “burn” water in a fluorine atmosphere. Or at least, so I hear. They never let us play with fluorine in high school chem lab :(.

They never let you do any of the fun stuff in HS chem.

Unless the science wing is due to be remodelled over the summer anyway. Yay thermite :smiley:

Man, y’all just didn’t go to the right school. For two weeks when our regular Chem teacher was out, we got to play with liquid nitrogen, sodium in water, napalm, and yes, thermite (melted out an engine block behind the building with potassium permanganate and glycerin as an ignition catalyst).

Gad, those were fun days. Thanks, Doc Glidden, you were the naz.

“A flame is a self-sustaining oxidizing chemical reaction producing energy and ionized gas (plasma).”

Visible flame is produced when electrons return to their usual energy levels (orbits) in a given element, producing photons. The energy mentioned above is mostly heat.
Loss of electrons is the most basic definition of oxidation. When a substance combines with chlorine orr flourine, for example, oxidation is taking place. The root of the owrd oxidation obviously comes from the word oxygen as it is the most common type of both rapid (combustion/exothermal) and slow (eg rusting, tarnishing) oxidation, observed by humans on Earth.

To be fair, Cecil was trying to cram a lot of info in a 600 word column. His answer covers pretty much all the fire anyone is likely to see outside a chemistry lab. I suppose he could have stuck a “usually” between “Oxygen fuel and heat are” and “The essential ingredients of fire.” But that might just have confused the questioner.

Especially since there’s a strong conflict between “usually” and “essential” :slight_smile:

uurrg. :smack:

Still I think my basic point holds. Cecil’s column covers all the fire we’re likely to see in daily life.

Well, I guess that depends on your line of work…

Liquid nitrogen? Yeah, liquid nitrogen is fun, but fluorine it ain’t. And I’ll bet that even your dear old Doc Glidden (who does indeed sound like a great teacher) didn’t let you play with fluorine.