⚗️ 5 — Self-Sustained Chemical Reaction

What is the self-sustained chemical reaction involved in flaming combustion?

A complex chemical chain reaction involving free radicals.

What are free radicals?

Highly reactive particles formed when fuel and oxygen molecules break apart during flaming combustion.

How do free radicals sustain combustion?

They combine with oxygen or elements released from fuel to form new substances and additional free radicals.

What effect does the free-radical process have on oxidation?

It increases the speed of the oxidation reaction.

What happens during combustion of methane and oxygen?

Methane breaks down and its elements recombine with oxygen to form carbon dioxide and water while releasing heat and light.

What toxic and flammable intermediate products can be produced during methane combustion?

Carbon monoxide and formaldehyde.

Why do more complex fuels produce different combustion products?

Their more complex chemical structures create different free radicals and intermediate products.

What is flaming combustion an example of?

A chemical chain reaction.

What initiates the self-sustained chemical reaction?

Sufficient heat causes fuel and oxygen to form free radicals.

What causes a fire to continue burning?

The chemical chain reaction continues as long as fuel and oxygen are available and the reaction is not interrupted.

What can stop the chemical chain reaction?

Consuming fuel or oxygen or applying enough extinguishing agent to interfere with the reaction.

What is chemical flame inhibition?

Using an extinguishing agent to interfere with the chemical reaction and terminate combustion.

What types of extinguishing agents can chemically inhibit flames?

Some dry chemicals and Halon-replacement agents.