Sciencemadness Discussion Board

Sodium chloride when using hydrogen chloride

MeSynth - 8-10-2011 at 14:02

Hi! My question is very simple.

If sodium chloride is dissolved in toluene or ether and then the maximum amount of hydrogen chloride gas is added will the sodium chloride precipitate out?

simba - 8-10-2011 at 14:59

And who told you sodium chloride will dissolve in ether or toluene?

peach - 8-10-2011 at 15:14

Why would NaCl dissolve in toluene to begin with? Try adding table salt to cooking oil and you'll notice it does not dissolve. Toluene belongs to the same group of solvents.

Do you mean adding sodium (insoluble in toluene) to the toluene and then gassing it?

If so, yes, it would. Although what'd be more likely to happen is that the lumps of sodium would form sodium chloride on their surface then not do much.

The hydrogen chloride isn't going to dissolve in the sodium dried toluene very well either.

I'd be interested, genuinely, to know what you were planning to do.

NaCl can be dried out by simply roasting the shit out of it in the open atmosphere. This is a standard chef trick for salt baked fish.

[Edited on 9-10-2011 by peach]

ThatchemistKid - 8-10-2011 at 19:38

I am a little sick at the moment, and maybe not thinking clearly, but I was wondering about electron flow...assumededly the HCl is not ionized in the toluene to any appreciable extent. Even if it were ionized the sodium would be donating to a chloride Ion I cant really even accept the AO diagram that is forming in my mind of this ion ....very unikely... The only positive charge lying around would be H+ in this situation and I highly doubt this reaction goes to sodium hydride (or this 2c 1e specices that this is suggesting). The reason that Na reacts with HCl solution I always imagined was that it first formed NaOH then that reacted with the HCl... by some Single electron transfer from sodium to a hydrogen of the water giving us a transient hydrogen radical that then reacted with another H radical an leaving 2Na+ and 2OH-.. which goes on to react with the HCl.this is then suggesting that if the same thing occured on the Na's surface in the toluene that the Na Would transfer an electron to the Hydrogen of HCl same mechanism occurs and NaCl solid forms. I do not know, this is all sick delirious speculation and I feel these reactions are much more complicated than I have made them out to be.

[Edited on 9-10-2011 by ThatchemistKid]

[Edited on 9-10-2011 by ThatchemistKid]

turd - 9-10-2011 at 14:38

Quote: Originally posted by peach  
NaCl can be dried out by simply roasting the shit out of it in the open atmosphere. This is a standard chef trick for salt baked fish.

I'm not sure what this thread is about, but note that NaCl is not hygroscopic, so "heating the shit out of it" seems a bit of an overkill. Actually I'm not aware of any NaCl hydrates. If your chef's table salt cakes, the most likely cause is that there are alkaline earth metal chlorides inside.

And what's that drivel about atomic orbitals? How could Nicodem miss this "gem"? :P

ThatchemistKid - 9-10-2011 at 17:51

This drivel about atomic orbitals was me sick and delusional last night, Luckly I am feeling better. I think I was trying to apply a lot of the new concepts I've been learning in grad school all at once to something that is.. not really related.

also Sodium chloride to my knowledge is hygroscopic.. even a quick wiki search yields this. Sodium chloride is sometimes used as a cheap and safe desiccant because of its hygroscopic properties.
NaCl crystals are soft and hygroscopic – when exposed to the ambient air they gradually cover with "frost". This limits application of NaCl to dry environments or for short-term uses such as prototyping.
Probably why NaCl Ir windows are stored in a desiccator huh?

overload - 9-10-2011 at 19:05

Quote: Originally posted by turd  
Quote: Originally posted by peach  
NaCl can be dried out by simply roasting the shit out of it in the open atmosphere. This is a standard chef trick for salt baked fish.

I'm not sure what this thread is about, but note that NaCl is not hygroscopic, so "heating the shit out of it" seems a bit of an overkill. Actually I'm not aware of any NaCl hydrates. If your chef's table salt cakes, the most likely cause is that there are alkaline earth metal chlorides inside.

And what's that drivel about atomic orbitals? How could Nicodem miss this "gem"? :P


Isn't that how you make dioxins? I remember reading about dioxins and how they are formed by heating salt to high tempuratures and then combusting them.

turd - 9-10-2011 at 22:36

Wikipedia is probably confused about the osmotic effects of NaCl solutions used to cure meat. That's not what you call hygroscopic in a chemical context.

Make a concentrated NaCl solution, place in a warm area and wait. You will get
a) a viscous solution
b) a crystalline NaCl hydrate
c) anhydrous NaCl (cubic crystals, no birefringence)
?
Reapeat with a hygroscopic salt (e.g. CaCl2)

Nicodem - 10-10-2011 at 10:51

What does this thread has to do with organic chemistry? Not that I understand what it is about, but it does not look organic at all. Moving it in the Beginnings section.
Quote: Originally posted by turd  
Actually I'm not aware of any NaCl hydrates.

I wasn't either before reading this post a couple of years ago. See also DOI: 10.1107/S0567740874007138 for its structure.

turd - 11-10-2011 at 06:21

Quote: Originally posted by Nicodem  
I wasn't either before reading this post a couple of years ago. See also DOI: 10.1107/S0567740874007138 for its structure.

Nice one! I should have known it.

woelen - 11-10-2011 at 09:38

I can confirm that NaCl is somewhat hygroscopic. The usual free flowing table salt has a very small amount of anti-caking agents added (can be K4Fe(CN)6, CaCO3 or MgO/MgCO3), 0.01% or so. If you buy reagent NaCl, then you see that it is a hygroscopic solid, it quickly starts caking when stored in air. Sodium chloride is not so hygroscopic that it liquefies.