Can anyone tell me what you would get if you mix Sulfuric acid with Salt?
You get an A+ on your homework if we answer the question correctly for you and scolded by the moderators for not placing this in the beginners section
of the forum or for failing to use the search engine.blogfast25 - 28-6-2010 at 08:35
Hydrogen Chloride gas and Sodium Sulfate in solution.
The bisulphate is formed at ordinary temperatures.
Sodium sulphate forms only on strong heating. . .
. . . 2HCl + 2NaHSO4
Anders Hoveland - 1-7-2010 at 19:11
I tried CaCl2 and NaSO4H. Interestingly, both of these are byproducts of the chemical industry, NaSO4H from making HCl, as described above, and CaCl2
was a big byproduct from the now outdated Solvay process for making baking soda. They used to try pawning off CaCl2 for road ice salt, and NaHSO4 was
made into pool pH (-) for cheap.
CaCl2 + NaSO4H --> CaSO4 (precipitate) + NaCl + HCl. I found I could boil out some HCl and condense it.blogfast25 - 2-7-2010 at 07:47
The Solvay process is now obsolete?watson.fawkes - 3-7-2010 at 04:54
As much as the correspondent might want to change the laws of physics,
the Solvay process continues to work just fine. It's not used in North America any more because the mineral trona is easier to dig out of the ground. I learned about trona when I ran into a fellow that worked on one of the mines, but it's also mentioned
in the Wikipedia article about the Solvay process.blogfast25 - 3-7-2010 at 06:49
Ah, yes, Trona, of course...psychokinetic - 3-7-2010 at 13:07
Sticky test tubes.Anders Hoveland - 5-7-2010 at 23:13
I was under the impression that a lot of HCl was made from the electrolysis of salt water (the chlorine generated was burned with the hydrogen
generated) to make PVC for pipes, and that NaOH was a byproduct from this, and a little CO2 is bubbled in to make Na2CO3. That was out of my science
encyclopedia set that now is discarded.
I am uncertain though.The WiZard is In - 6-7-2010 at 05:42
I was under the impression that a lot of HCl was made from the electrolysis of salt water (the chlorine generated was burned with the hydrogen
generated) to make PVC for pipes, and that NaOH was a byproduct from this, and a little CO2 is bubbled in to make Na2CO3. That was out of my science
encyclopedia set that now is discarded.
I am uncertain though.
Most HCl is not manufactured - it is a waste product.
Production of vinyl chloride and (when it was still used for
dry cleaning) perchlorethylene produces large amounts of
HCl which is then used down stream.
Electrolysis is an expensive way to make an low value
product.peach - 7-7-2010 at 14:02
2NaCl + H2SO4 ---> SHIT that SMARTS!MttLsp - 11-7-2010 at 19:28
There are two possible reactions
2NaCl + H2SO4 --> Na2SO4 + 2HCl
This reaction is good if you intend to run the HCl through water to get H3O+ and Cl- (Hydrochloric Acid) since it will produce a higher yield of
hydrogen chloride gas.
However, if your are looking to make some Sodium Bisulfate (NaHSO4) then the reaction will be:
NaCl + H2SO4 --> NaHSO4 + HCl
*Carry out both reactions in a fume hood!!!*
Melgar - 11-7-2010 at 20:01
A nice reaction for generating a steady stream of anhydrous HCl gas is to mix H2SO4 with CaCl2. It does tend to foam, which can be mitigated by
silicone oil, and by only filling the container like 1/4 full. This reaction is a more efficient use of H2SO4 than using NaCl, since it uses every H+
ion. However, the NaCl reaction is better if you have plenty of H2SO4, since NaHSO4 is more soluble in water and thus much easier to clean up
afterwards.MttLsp - 12-7-2010 at 14:26
I'm confused...if I used two moles of NaCl for the reaction or 1 mole of CaCl2, I would have 2 moles of HCl either way. So aren't both methods of
equal efficiency if stoiciometric amounts are used?bbartlog - 12-7-2010 at 18:05
See what hissingnoise posted, above. At normal temperatures, NaCl only gives you NaHSO4, so you only get one mole of HCl from a mole of H2SO4. Whereas
CaCl2 gets you two moles of HCl from each mole of H2SO4. zed - 13-7-2010 at 11:33
Sigh. I remember when reagents were so plentifully available, and so cheap, that getting a little extra HCl from your H2SO4......Would never have
been a consideration.Chainhit222 - 14-7-2010 at 12:22
This is known as the salt cake reaction. I have done it before to get sodium sulfate. I mixed it up in a glass salad bowl in the fume hood (like 400
grams of salt and however much h2so4 you need), then I poured it into a baking dish and put it on the barby at a low temperature to get rid of the
HCl. You can then recrystallize it. peach - 17-7-2010 at 07:33
Hmmmm, I'm not so sure about this CaCl2 mentioning.
I was just trying to work out which would be economically cheaper for producing HCl, NaCl or the aforementioned CaCl2.
Seems I can get 25kg bags of table salt for around £17 - 18. CaCl2 is around £35, plus £8-10 delivery, making it about £43 - £45. Whereas I can
pick the table salt up somewhere in person. I think both table and Ca salt are around .2H2O hydrates, putting them on equal footing there. But,
looking at the boxes of CaCl2 I can get, it says they're around 70-80% pure, whereas table salt is more like 99%. Assuming the impurities won't
produce HCl(g), which may be incorrect, I get...
1kg table salt = ~68p
1kg CaCl2 delivered = ~£1.76
I'd also need around 20% more CaCl2, making it ~£2.11 per equivalent kilo. The calcium salt produces double the moles of gas, chopping it back down
to ~£1.06 for the same volume of gas, 38p more than the table salt.
Even if I use the raw price of the 25kg bag, undelivered, and assume it's 100% pure, it still works out at roughly the same price per mole of gas
released.
The densities of the two are theoretically almost identical, the CaCl2 does tend to come as flakes, which won't pack as nicely.
One advantage of it is obviously getting more gas per unit volume of salt; more from the same size flask essentially. The financial cost per unit of
gas is about the same it seems.
A massive sack of pure, cheap, dry CaCl2 would be nice though.
I've had the cake pop the flask on rinsing. I'll probably use plastic for that part in the future (xDPE).
[Edited on 17-7-2010 by peach]blogfast25 - 17-7-2010 at 08:17
Both NaCl and CaCl2 are usually completely dry when bought in retail.
You can buy anhydrous CaCl2 OTC from hardware stores as 'Drymate' or such: as a dehumidifier for cupboards, wardrobes etc. Slightly more expensive
than NaCl (but about as pure, in fact the main contaminant will be NaCl).
How much HCl are looking to produce and what for? For small scale the cost of the chloride isn't worth taking into account.
