Two Things...

[Daphuk_up]

Ok, first, an interesting discovery.  Apparently hot methanol vapor turns JB-weld into this soft, putty like substance.  It does not go back to epoxy-hardness after it dries either.  Interesting and unexpected.

Secondly, can anyone raise an objection to creating aqua regia by bubbling hot red HNO₃ gas (created from the infamous NaNO₃+H₂SO₄ reaction) directly into an ice cold jar of HCl (31%, Muriatic Acid)?  Will the HNO₃ cause the HCl to come out of solution, or will the HCl make is so there is no 'room' for the HNO₃?  Heh, I am probably going to try it before anyone responds to this thread, but still, I thought I would ask.  As always, help from more knowledgeable bees is appreciated.  

[El_Zorro]

That red gas isn't HNO₃, it's NO₂ gas generated by the decomposition of the NaNO₃.  In order to get the HNO₃, you have to do the reaction slowly and cooled and distill ovr the HNO₃ liquid.

If you're worried about the HNO₃ vapors, maybe you could put an amount of water in your recieving flask that would amount to an end amount of 70% nitric, then distill.

But as for a question of mine, has anyone tried just putting some conc. sulfuric in a flask, and adding an amount of DCM, then adding a slight excess of NaNO₃, and filtering, so you would end up with a solution of pure HNO₃ and DCM, without all the nasty fumes?  Would that work?  Of course, you would do it all with a heavily cooled flask, and maybe slowly distill off the DCM with a lukewarm water bath.

[Daphuk_up]

Hmm, but SWID was under the impression that NO2 is a brown gas, wheras HNO3 is a red gas.  (Fuming red nitric acid?)  Is this a misconception that SWID has absorbed from questionable sources?  When you distill nitric acid, what color is it?  Clear?

SWID has never tried using DCM, as SWID usually uses the 35% H2SO4 available for car battery refills.  (i.e., water is my medium)  An interesting proposition, SWID may try it sometime.  

EDIT:(A check of the Merck showed me that fuming nitric is by definition a red/brown gas/liquid, due to the coloration by the nitric dioxide.  That being the case, I guess it is good that my currently running expierament is causing bubbling in the recieving vessel (and the gas is colorless, and the liquid solution is not boiling in the reactant flask). 

[El_Zorro]

Hmmm...  Well, fuming red nitric means that it's so pure that it has slightly decomposed to some NO₂ in the prescence of heat and light, which is a red/brown gas.  If you distill aboslutely pure HNO₃, you'll get a clear, or maybe slightly yellow liquid.  But if you use some sulfuric that isn't sufficiently anhydrous, you'll get a solution of nitric and water.  Which is fine for aqua regia, I guess, depending on ow concentrated it is.  But I was talking about getting the pure shit and diluting it to you needs from there.

[Daphuk_up]

Heh, yea, I just figured all of that out.      

[Daphuk_up]

Ok, so I have a HCl+HNO3 solution of unknown stoicheometry, and I also have a solution of Sodium Sulfate+HNO3.  The question is, will sodium sulfate interfere in the chlorination reaction of Palladium?  Palladium Sulfate doesn't even have a Merck entry, so it seems a less likely product.  Of more concern is the oxygen in the sulfate ion becoming free.  Any ideas, suggestions, hints, or cryptic answers?

(Note that my idea is to combine the HCl+HNO3 mixture with the NaSO4+HNO3(+HSO4?) in order to raise the concentration of HNO3, which I would guess to be on the order of ~10%.)

[Daphuk_up]

Ok, decided to take a bit of a risk.  After taking a small sample of the NaSO4+HNO3 mix and adding some muriatic to it, I decided that since the HCl wasn't forced out of solution the H2SO4, if any, was in low concentration.  That being the case, I went ahead and mixed all of the NaSO4 containing mixture with 2x the amount of the HCl+HNO3, and dropped a palladium chip in there.  (the palladium I have is in ~2mm thick plates).  After sealing the reaction flask with a pressure control valve (I taped a balloon on it   ), I have decided to let it sit at room temp until the chip dissolves.  Then reflux as best I can (ghetto condenser is made of 1/4" copper tubing, so not suitable for most acids...on the other hand, it has a 7ft(213cm) distilling path   ).  The results will be seen...eventually.  Hey rhodium...I like using the dot dot dots...they are cool...dont you think so too?... ...

[El_Zorro]

You're going to reflux aqua regia using a copper reflux condenser??  The point of using aqua regia is to dissolve metals that are normally too inert to be attacked by acids.  In other words, if it already hasn't happened, and filled your lab with HCl and HNO₃ vapors, as well as maybe some NO_X fumes, your condensor is gonna be silly putty in a very short amount of time.

[Daphuk_up]

El Zorro, oh good lordy no.  SWID was stating that the only condenser SWID has is made of copper and that was why SWID wasnt going to use it, and was the reason that SWID had to 'reflux as best as he can'.  In all likely-hood, a three foot length of chemically resistant 1/4" non-cooled tubing will be placed vertically above the reaction vessel.

Oh, and update:  SWID's container of aqua regia has turned decidely brown (HNO3 -> H2O + NO2), and the palladium metal turned blackish, only very slightly visibly dissolved. >_<  SWID's supply of sodium nitrate being limited, he has to wait another day before creating more nitric acid.  (SWID desperately needs to buy or build a better, more chemically resistant condenser, so he can create HNO3 seperately and combine in exact porportions.)  SWID expects this next time to reflux directly after creating the aqua regia and dropping the palladium in it.  It seems that aqua regia, even if kept in a dark place, will decompose over night.  SWID does note, however, that the aqua regia stored in the refridgerator has not decomposed...the solution with the paladium chip in it was stored at room temp. 

[El_Zorro]

Maybe that brownish red color in your aqua regia is the PdCl₂ going into solution.

[Daphuk_up]

At this point, SWID is not even going to bother to say "Well, duh." or "My god I am a moron".  SWID will quietly, humbly, and in shame accept his idiocy.

(SWID assumed that since it was chloride, it would probably be green.  Guess what, SWID didn't make an ass out of anyone else.  *sigh*  Read, research, learn precise info and data, this SWID must do.)