RRB Group-D Model Paper 16 with answers for online practice

Sooty flame

• The unsaturated hydrocarbons like alkenes, alkynes are aromatic hydrocarbons that partially burned with a yellow sooty flame.
• It is due to incomplete combustion of the hydrocarbon in air.
• A large amount of carbon does not completely oxidize in the air and gives sooty flame.

Non-Sooty flame

• The saturated hydrocarbons burn with a Blue colour non-sooty flame.
• Alkanes are saturated hydrocarbons and classified as a type of aliphatic hydrocarbon.
• Hexane is a type of Alkanes that burns with a blue non-sooty flame. Hence option 2 is correct.
• The blue flame emerges when the complete combustion of carbon takes place.