HCL Bubbler Question

[chemstu1320]

Swim wanted to do a test with some collected items used in the HCL bubbler setup.  Swim hopes some bee's will lend some knowledge on my reaction.  Swim used NaCL (no iodized), wet it with HCL (%31), and then dripped some concentrated sulfuric acid on.  Swim noticed black bubbling and foaming but no visable gas was seen to be produced.  Swim has never had any experience with this reaction, and wonders if everything happened as it should.  ThankS!

[Stonium]

Leave out the HCl. There's water in it (whiich may be the reason for your problem) and you don't need it to generate HCl gas. Plain and simple: Just drip concentrated H2SO4 on NaCl. Voila. HCl gas is generated. It doesn't matter if one uses iodized or non-iozed NaCl.

For optimum results, everything must be dry.

[chemstu1320]

Swim tryed simple NaCL and added the sulfuric acid, and I quickly moved upwind! ;-)  This makes Swim ask why every write up envolving a HCl bubbler setup Swim has read so far called for wetting the NaCL with muriatic (%31 HCl) before dripping the sulfuric acid.......??  Thanks again Stonium!!

[ApprenticeCook]

HCl gas is not the best to be around so yes upwind was a good move...
and what synths are you talking about? i dont remember any saying that...

-AC

[chemstu1320]

DDrool's was the one Swim found it in. "I had two bad experiences with HCl generators before I figured out how to do it.  This is the way: Add NaCL (lot's non-iodized) to a two-necked flask.  A big one (2liters) is good.  Wet the NaCl with HCl, but not too much (no puddles)."

So Swim followed this method.  But if H2SO4 is only needed to be dropped over NaCl to generate the gas that will be directed through a Vigreux column filled with CaCl2, and then directed into a solution to make fun crystals.... SWim is down with the clown. ;-)     Thanks again for info to help Swim get learned on the matter!!

[ApprenticeCook]

look on rhods for a better generator, personally hate the NaCl method.... had a bad run with it a bit back...

the way swim does it is to use HCl aq dripping onto CaCl₂ then through another dryer (inline type OTC from rhods site) with CaCl₂ then into FB.

-AC

[Stonium]

Why complicate the issue?

Take a 20 oz plastic soda bottle and dry it out completely. Fit it with a 1 holed stopper. Fit the stopper opening with an appropriate length of plastic tubing. Add the aforementioned ingredients and HCl gas (dry enough for most of our purposes) is generated and flows out through the tubing. Stick the tubing into the solution to be gassed and there you go. You're doing it.

[chemstu1320]

No doubt of the simplicity of that method.  Not to mention the ability to shake up the bottle to improve the reaction between the NaCl, and the H2SO4 which would generate more HCl gas.  But two questions arise from your recommendation. 

1) Would this reaction get hot enough to melt the plastic bottle???

2) What about the anhydrous conditions required for MDMA.HCl Crystallization to fall out of solution???

[Stonium]

1) Would this reaction get hot enough to melt the plastic bottle???
No. Not if one doesn't get carried away with things, anyway. The bottom of a COMPLETELY DRY soda bottle is covered with a 1/2 to 1 inch layer of NaCl. Some amount of H2SO4 onto the NaCl to generate Hcl gas. How much depends on how much Hcl gas one desires to generate. Starting out smaller is better because it is easier to generate more than it is to get rid of too much.

2) What about the anhydrous conditions required for MDMA.HCl Crystallization to fall out of solution???
As I said, this method will generate gas dry enough for most of our purposes. that of crystallizing MDMA HCl included.

[Vitus_Verdegast]

Nowadays I always make the HCl generator by filling the bottom of an empty dry HDPE bottle with some CaCl₂, and add some concentrated hydrochloric acid to this (just a few aliquots, don't flood the thing!). The rubber stopper is placed on and the tubing is connected to a small washing bottle filled with CaCl₂ to completely dry the gas.

Just squeeze the bottle. This way one can work outside a fume hood without too much health risks, as gas will only come out when the bottle is squeezed. It also obliterates the need for a suck-back device.

I prefer it over the H₂SO₄/HCl/NaCl generator any day of the week.

[jammin]

In your post you said just CaCl2 and conc. HCl.
You dont need h2so4 in this setup?

[ApprenticeCook]

The use of CaCl₂ (imho) is safer than the NaCl method, i think i read somewhere that if you dont keep shaking up your NaCl the acid creates a "mound" of Na₂SO₄ which the acid will not react to and you can get a build up of the acid on this then once theres enough to roll of this mound of product salt there can be a massive reaction of gas generation.

The CaCl₂ method is good as its only absorbing water, and if the top few mm of CaCl₂ gets to max absorbance the water will pass through until it hits the next few mm which are water free, hence no buildup... safer...

is that right or as usual am i rambling on about crap?

In your post you said just CaCl2 and conc. HCl.
You dont need h2so4 in this setup?

No.
CaCl₂ will dry the wet HCl to gas and be done with it, the only need for H₂SO₄ is for the NaCl generator.
Look at rhodiums site for the gas generator setup document.