Sciencemadness Discussion Board

discoloration of glacial acetic acid

jamit - 3-10-2021 at 02:25

So i purchased a liter of food grade glacial acetic acid -- concentration 99.85%. I've stored it at room temperature for 2 yrs and notice a discoloration from crystal clear to a tint of yellow. Obvious something has happened, perhaps a decomposition or degradation of acetic acid. I plan of redistilling the acid so as to purify it, but any idea what happened? Why the yellow tint?
I looked up "decomposition of acetic acid" and nothing rings a bell for me. Any guess what might have happened to the glacial acetic acid?
Any help will be appreciated. thanks.

draculic acid69 - 3-10-2021 at 02:53

The bottle or lid might be breaking down and causing the discolouration

jamit - 3-10-2021 at 03:23

You might be right.. the rubber inner part of the cap is discolored and eaten away. Thank you!