Chemical Engineering - Chemical Engineering Basics - Discussion

Incombustible - Not capable of igniting and burning.

Is one of the example of Halons, which is fire extinguisher.

CCl4 hasn't capable of igniting, burning.

It is used as dry cleaning solvent and refrigerent.

H2, C2H2 and S all undergoes combustion reaction with O2. CCl4 is not flammable, it is known as halon used in fire extinguishers.

I can't understand clearly, why it is incombustible? can you please explain about it?

Because CCl4 does not combustible reaction so not use fire extinguisher.

The structure of CCl4 is tetrahedral which is geometrically stable and other such as C2H2 has unsaturation moreover S has lone pair electrons in its hybrid d orbitals and H2 also has 1s bonding which the combustible heat energy is evident to break the relevant bond energy in comparison to CCl4

Give me few other example apart from ccl4 which is incombustible.

Combustion means reaction with oxygen or burning in layman's term.

Hypothetically, for combustion of CCl4 , the following reaction would have occurred :

CCl4 + O2 -> CO2 + 2 Cl2

For feasibility of any reaction, the sum of bond energy of all the products should be less than sum of bond energy of all the reactants.

In this case, breaking of O-O, and four C-Cl bonds require more energy than forming two C-O and two Cl-Cl bonds. Hence, CCl4 does not react with Oxygen and is incombustible