HYDROCARBONS

ALKANES AND THEIR RXNS

Free Radical Substitution

Alkanes undergo a reaction involving three stages - initiation, propagation, and termination, where free radicals are formed and react to produce products.

Combustion

Alkanes burn in oxygen to produce carbon dioxide (CO2) along with carbon monoxide (CO) and water.

Cracking

Long-chain alkanes are broken down into alkanes and alkenes through thermal or catalytic processes

Conditions for thermal cracking

800 C

Reforming

Straight-chain alkanes are converted into branched or aromatic compounds through a reforming process.

Conditions for catalytic cracking

zeolite and 500C

Does thermal cracking often produce free readicals?

yes

What is the equation for ther initiation step of alkane FRS

Cl2 ——— *Cl + *CL

Propagation step in FRS equations

*Cl + CH4 ———— *CH3 + HCl

*CH3 + CL2 ———— CH3CL + *CL

Terminaiton of alkane FRS eqn

*CH3 + *CL————CH3CL

*CH3 + *CH3 ——-C2H6

Name the four types of reactions alkanes undergo

cracking, combustion, free radical substitution, reforming