Sciencemadness Discussion Board

Drying chloroform with MgSO4? how?

Agent MadHatter - 22-7-2009 at 20:06

Hello everyone. I just joined and I have a very small chemical background, so if you could give me a break. I try to research as much as possible before posting but this one stumped me.

I'm trying to follow an extraction procedure following this-
"Cool to room temp and wash the mixture with 200 ml of 1 M ammonium hydroxide. The chloroform solution was dried with MgSO4 (this would have to be after separation), filtered, and concentrated by evaporation in vacuo under a temp of 38° "

And I'm completely lost on this part.

The mixture of chloroform should be refluxed until it is reached (how will you know?) then adding different chemicals until a certain color is reached (depending on which chemicals added) and then your supposed to do what was copied above.

Can someone explain this with alittle more detail please?

If not, can someone point me in the right direction to learn more on the topic?


Arrhenius - 22-7-2009 at 20:14

Add some solid anhydrous magnesium sulfate to the chloroform layer (after you've washed it with base. DO NOT USE SODIUM HYDROXIDE!), stir it up, let it sit for a little while and filter off the magnesium sulfate. Should be that easy. This removes enough water that you don't end up with a puddle of it in your flask when you evaporate the chloroform.

As for your reactions... who knows... you haven't told us what they are.

ammonium isocyanate - 22-7-2009 at 20:20

Huh?

What is the question you're trying to ask? It would be alot clearer if you would post the whole procedure you are talking about.

Quote:

I'm trying to follow an extraction procedure following this-

Extraction of what?

Quote:

The mixture of chloroform should be refluxed until it is reached (cut)

Until what is reached?

If your asking about how chloroform is dried using MgSO4, then the answer is that magnesium sulfate attracts water from solvents, air, etc, acting as a dessicant and forming hydrated crystals that won't lose water without sufficient heating. If that isn't a sufficient explanation, wikipedia the word dessicant.

No offense, but it looks like it would do you some good to hit the books before posting more questions like this.

Agent MadHatter - 22-7-2009 at 20:22

Thank you for the fast replies.

What I meant about refluxed is the chemical procedure stats to reflux it until and I quote " reflux in a 3 necked flask. As soon as you have the reflux adjusted"

My question is, how will I know when its adjusted?

What would the goal be by refluxing? To boil it?

ammonium isocyanate - 22-7-2009 at 20:27

Again, this would be alot clearer if you would post the whole procedure you're talking about. Giving us parts of sentences doesn't help much. We aren't mind readers.

Quote:

What would the goal be by refluxing? To boil it?

I suggest that you follow the wikipedia link provided in your other thread on refluxing. Refluxing is a technique designed to supply energy to a reaction while specifically avoiding boiling away the solvent/reactant.

Arrhenius - 22-7-2009 at 20:28

http://www.erowid.org/archive/rhodium/chemistry/lsd-buzz.htm...

This one?......

I seriously doubt you'll be able to make any LSD by cookbooking.

[Edited on 23-7-2009 by Arrhenius]

Agent MadHatter - 22-7-2009 at 20:31

LOL

If I can't do a simple salt extraction I don't think I can make LSD!


Ammonium: I thought you want to boil it, and thats what the condensation chamber is for? To prevent loss of chemicals? Or is it as a back up if you do start to boil it?

ammonium isocyanate - 22-7-2009 at 20:36

Sorry MadHatter, I misunderstood you...

The point of reflux is to heat a reaction mixture to its bp while keeping any liquid from boiling off by immediately condensing the vapours back into the reaction chamber. What I thought you were asking was if reflux was to boil off all the solvent.

Seriously though, if you want any help with whatever you're trying to do you need to tell us what the procedure you're trying to follow is.

Agent MadHatter - 22-7-2009 at 20:39

So I'll know when the reflux is adjusted when its boiling at its boiling point? So a low boil?

ammonium isocyanate - 22-7-2009 at 20:43

Thats how it looks from what little you gave us to work off of. Generally, once a reaction is refluxing it is allowed to do so at constant heat for anywhere from 30 min to several days, depending on the bp of the solvent and the reaction taking place.

MadHatter, this is the last bit of advice I will give you on the subject until you actually say what reaction you are trying to perform. Secrecy is not appreciated at sciencemadness.

Polverone - 22-7-2009 at 22:53

Quote: Originally posted by ammonium isocyanate  

MadHatter, this is the last bit of advice I will give you on the subject until you actually say what reaction you are trying to perform. Secrecy is not appreciated at sciencemadness.


Neither is helping would-be drug cooks with "recipes" appreciated. I don't know if you (the hatter, not ammonium isocyanate) are supplying so little information because you don't want to be attacked as a drug cook. A bit of advice: if you were hoping to follow some drug recipe and withheld information for that reason, don't even say so. Since you are trying to learn the basics, ask for help with a similar but non-drug-related procedure since people will gladly help you, you don't need to hide anything, and the skills are quite transferable if you hope to apply them to something nefarious later. Walk before you run. You need to learn basic terminology and lab techniques and you can easily learn them using substances that are readily available, cheap, legal, and will never attract opprobrium on the forum.

If you are withholding information for some other reason, you should just copy the procedure in full into this thread and I have wasted a little speech.

[Edited on 7-23-2009 by Polverone]

Paddywhacker - 22-7-2009 at 22:59

yes indeed.

Also, it looks like vyour knowledge of chemistry is such that you risk misinterpreting the instructions, and then asking advice based on those misinterpretations. Giving you advice on that basis could be dangerous, if not just plain unhelpful.

You should have posted this in the Beginnings forum.