Sciencemadness Discussion Board

Triphasic mixture forming after salting out toluidine

SuperOxide - 29-5-2022 at 13:55

I'm right in the middle of a workup for an o-toluidine synthesis procedure where I'm steam distilling off the toluidine then salting it out with NaCl. I've done this same procedure twice before, but this time after adding the salt, it seems to have formed a triphasic mixture, which I don't remember happening at all.


more pictures here

I'm certain that I've added enough salt, because you can see not all of it's gone into solution indicating that it's been saturated. I have also shaken it quite a bit just to be sure.

The only thing that was different this time was that when I started the steam distillation, there was a foam over. But I just washed everything into the RBF and steam distilled again.

Has anyone see this before? I'm sure it's something simple that I just haven't encountered before.

RustyShackleford - 29-5-2022 at 14:30

Doesnt look like a true third phase to me from the haze at the bottom. How long did you let it settle before taking that pic? i think if you wait overnight or such it might go away.

SuperOxide - 29-5-2022 at 14:32

Quote: Originally posted by RustyShackleford  
Doesnt look like a true third phase to me from the haze at the bottom. How long did you let it settle before taking that pic? i think if you wait overnight or such it might go away.

Funny you say that, I was just thinking that. I took those pictures a few hours ago, and I just went and looked at it and it looks like it has gone up a bit. So Im going to agree with you there.

Odd though, i've never seen this before. But ill see if it goes away over night.

Tsjerk - 29-5-2022 at 23:36

That is an emulsion, maybe you can add a different salt which makes a denser solution.

SuperOxide - 30-5-2022 at 13:00

Quote: Originally posted by Tsjerk  
That is an emulsion, maybe you can add a different salt which makes a denser solution.

No, Rusty was right, it cleared up overnight. I guess I was just surprised because I hadn't seen that happen before. It seemed to move around independently on the bottom when I moved the flask around, just like a bottom layer. My mistake.

Tsjerk - 30-5-2022 at 13:11

I didn't say Rusty wasn't right, an emulsion is a non-homogenous mixture of two liquids. Sometimes they separate, sometimes they don't.

[Edited on 30-5-2022 by Tsjerk]