The following fuels are burned in laminar jet flames each wi

The following fuels are burned in laminar jet flames, each with a mass flowrate of 3 mg/s: acetylene, ethylene, butane, and isooctane. Which flames emit soot from their tips? Discuss your answer.

Solution

Acetylene and ethylene will emit more soot (acetylene the most).

As the number of C-H bonds increase, the tendency to oxidise properly increases.

Acetylene (C₂H₂) has the least number of C-H bonds so its tendency to oxidise is less.

As the oxidation is better, lesser is the chance of soot formation.

Therefore, in case of acetylene, oxidation tendency is lesser, so the soot formation wil be more followed by Ethelyne (C₂H₄)