# When I burn isopropyl alcohol (IPA), it burns orange. But when I burn ethyl alcohol, it burns totally blue. Why is this? Tags: alcohols, combustion, hydrocarbons - Score: 15 - Views: 16442 - Answers: 3 - Answered: yes - Asked by: Pushies (176 rep) - Asked: 2020-03-23 - Edited: 2020-03-24 - Site: chemistry ## Question I burned them in a small aluminium tray. While IPA is burning orange, it produced the smell of soot, but while ethanol is burning blue there isn't any smell. Also, ethanol made the tray really cold when I poured it on the tray before burning it, compared to isopropyl alcohol. How can this be explained? Note: IPA concentration is 99%, Ethanol is 97% ## Answers ### Answer by ACR (score: 18 [ACCEPTED]) Interesting observation. The blue flame color of all hydrocarbon fuels is due to the emission small diatomic carbon species such $C_2$ or CH. There is nothing magical about IPA having a yellow flame. The yellow flame originates from incomplete combustion. There is more carbon per mole of IPA as compared to ethanol. Yellow flames are called reducing flames and blue flames are called oxidizing flames. In older times when Bunsen burner was taught in detail, it was