copperastic
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Hydrochlroic acid
Hi, I was in my basement today and i saw two bottles with black stoppers. I put on gloves and took them out and it was labeled muriatic acid. The acid
was yellow so is it more pure then clear acid from the hardware store?
P.S. When my dad was buying the house he told the people that used to live there that they don't have to take everything from the basement and they
said ok so im guessing it was theirs.
P.P.S The bottle had a white powder on it do you know what that would be?
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HgDinis25
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Muriatic acid is hydrochloric acid. Clear acid is much more pure than yellow acid, as the yellowish colour comes from iron impurities.
About the powder, check around to see if there's a source of ammonia. When ammonia vapours and HCl vapours come in contact they make ammonium
chloride. Because stoppers allow tiny quantityes of gas to come out, it could have formed the ammonium chloride.
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thesmug
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I am not sure on why the acid was yellow, but a yellow color is an indication of impurity, not of purity. If you could describe the white powder a
bit more, I should be able to tell what it is. Try mixing a tiny bit of it with a bit of baking soda in water. If it is some sort of residue from the
HCl, it should fizz. There is also a chance that the bottles were mislabeled and actually contain H2SO4, which is slightly yellow like you described.
You can test for H2SO4 by dripping some of the acid on paper. If it blackens or dissolves very quickly, it's H2SO4.
[EDIT] Darn, the guy above beat me to it! Amm. chloride seems much more likely. You can still test for H2SO4, though!
[Edited on 3/15/14 by thesmug]
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copperastic
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Ok ill try that thanks.
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Zyklon-A
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Pure sulfuric acid is colorless.
Why would the hydrochloric acid leave a residue? It couldn't be that impure, I think.
If the acid is of decent concentration, then you could do a smell test. HCl has a strong smell, while sulfuric acid has no smell a room temperature.
I highly doubt it's sulfuric acid.
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thesmug
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Quote: Originally posted by Zyklonb  | Pure sulfuric acid is colorless.
Why would the hydrochloric acid leave a residue? It couldn't be that impure, I think.
If the acid is of decent concentration, then you could do a smell test. HCl has a strong smell, while sulfuric acid has no smell a room temperature.
I highly doubt it's sulfuric acid. |
I've seen many samples of OTC H2SO4 be very yellow because of dissolved elemental sulfur and other impurities. From how he described his samples, they
don't seem like they are likely to be very pure. And about the residue, I apologize for not being as clear as I should have been. I was talking about
residue from other materials having been mixed with/come into contact with the acid.
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woelen
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OTC H2SO4 may have a color, but not due to dissolved sulphur. Sulphur does not dissolve in H2SO4, not at all! Not even at 250 C. I tried it some years
ago in an attempt to make blue sulphur-compounds analogous to the red and green compounds made from tellurium and selenium:
http://woelen.homescience.net/science/chem/exps/SSeTe_H2SO4/...
Pure hydrochloric acid and pure sulphuric acid are colorless. OTC sulphuric acid frequently is brown, due to charred organic impurities. OTC
hydrochloric acid (muriatic acid) usually is yellow, due to iron-impurities and also possibly due to organic impurities. I once distilled some of such
muriatic acid and this yields a very nice colorless liquid with well over 20% of HCl, which is very pure and much better for home chemistry
experiments.
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Texium
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Some OTC chemical companies will also dye sulphuric acid brown to "alert people to its hazards" according to Wikipedia
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thesmug
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| Quote: Originally posted by zts16 | | Some OTC chemical companies will also dye sulphuric acid brown to "alert people to its hazards" according to Wikipedia |
I've seen that before. I've actually seen it be blood red and extremely thick (like syrup) before.
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HgDinis25
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I've also seen 96% Sulfuric Acid being sold with a blue dye, looking a lot lie blue denaturated alcohol.
The one I buy, though, is completly colourless.
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