[amphoteroi]

Hi everyone! First post here.

In my Organic Chemistry class, we are working on identifying unknown substances. I'm currently working on my liquid unknown, and I have reason to believe it is Acetic Acid, though, I had one confusing thing happen in lab.

Why I think it's acetic acid:
-The IR looks, painfully similar to some I found online. Big broad OH, C=O, etc.
-Experimental Boiling point was about 116 °C, (theoretical is 118.1 °C for acetic acid)
-I burned it, it's not aromatic.
-Soluble in water, so it probably has less than five carbons.
-Makes a ton of bubbles when added to sodium bicarbonate.. it's definitely acidic.
-This stuff STINKS. Like a rotton vinegar foot.

Why I'm confused:
-I did a halogen test, dipping a copper wire in the liquid unknown and putting it over a flame.
The test says if it burns green, a halogen is present. Well, I did this several times and, not every time, but a couple times, I definitely saw a green flame. >_>

That just screwed me all up. Any carboxylic acid with halogens has a MUCH higher boiling point, so something isn't right here!

My question is, is it possible for this to be a false positive? Yes, I know I should do additional tests and I will when I return to lab. I am curious if Acetic Acid reacts with the copper, maybe, in such a way that it turns green anyways.

is there something else with a similar melting point etc. that smells like a rotton vinegar foot? Haha, Or does anyone have any pointers? I'd much appreciate it!

Thanks!

[enahs]

If you have some amount of copper hydroxide on your copper (which is likely) and then react it with acetic acid you will get copper (II) acetate.  Copper (II) acetate I suspect would give a green flame. Heck, Copper (II) hydroxide probably would too.

[408]

the smell is all you really need here....