Sciencemadness Discussion Board

Red Acetone?

TheNerdyFarmer - 21-2-2017 at 08:08

Hello, I have some acetone that has gradually turned red over the period of a month. I am not sure why though.

What I did was I was making sodium nitrate via Ammonium nitrate and sodium hydroxide. The NaNO3 product was slightly yellow so I decided to try and clean it with acetone in hopes that the yellow stuff would dissolve in the acetone. And some of it did. I gravity filtered the dirty acetone into a Erlenmeyer flask. I will note that the flask was not super clean, it just had a little bit of sodium carbonate in it. Gradually over time it began to turn a bright orange. Kind of like a dichromate solution. But then after some time turned to a very bright red. I tried experimenting with it a bit and got some strange results.

I started by burning it. It burned about halfway and then stopped. There was some slight charring on the side of the evaporating dish and in the center was a very viscous orangey red, not flammable, liquid.
With this liquid i tried to do some tests to see how it reacted in acidic conditions. I used sulfuric acid for this. I added a drop of the H2SO4 in the contents of the dish and a blue liquid formed and upon stirring diffused throughout the solution.

Please help me identify what this is and how it could have formed. If pictures are needed please tell me. Thanks in advance :D

[Edited on 21-2-2017 by TheNerdyFarmer]

JJay - 21-2-2017 at 08:38

I am guessing that the red material was an aldol condensation product.

I don't know what the blue liquid was.

Amos - 21-2-2017 at 11:47

You have an aldol product as JJay said, due to sodium hydroxide and/or ammonia contamination of your acetone. The blue compound might be a nitroso compound or nitrous acid formed through any number of routes involving ammonia or nitrate contamination as well. I would just re-distill this acetone and see if the distilled product still turns dark over time. Don't distill all of the liquid though, just what boils at acetone's b.p.

TheNerdyFarmer - 21-2-2017 at 15:24

Okay thanks. I will try and get around to distilling it and update on the progress when I am finished.

PHILOU Zrealone - 22-2-2017 at 15:00

That's it when allowing aceton and NH4OH to stay for a few mothes...I observed the same as you...the aceton had turned a viscous resin because of multiple crotonisation-condensations...

The same happens with aceton and NaOH...turns orange, then red, then brown and black upon time and while viscosity increases.