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neutrino
International Hazard
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That should work.
Cyclonite: I was referring to tom’s unbalancable equations.
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Archimede
Harmless
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My teacher was always getting mad when he saw chunks of alluminum in the ferric chloride we used to etch circuit boards.
I saw it for sale at radio shack but I didnt read the label to see what exactly its in the bottle.
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Magpie
lab constructor
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I've just gotten a pleasant surprise from the marketplace, for a change:
I bought 100g of photographic grade ferric chloride fully expecting it to be FeCl3*6H2O or FeCl3*4H2O. To my surprise it is very dark in color,
appears red-purple in transmitted light, and is agressively hygroscopic. I have some sitting in a watchglass in front of me and within 15 minutes it
has swelled up and changed color to light brown. It may well continue to lighten up to the hexahydrate which Wiki says is yellow.
The reason I am so happy is that it appears that I am now the proud owner of a Lewis acid.  Can this be true?
The single most important condition for a successful synthesis is good mixing - Nicodem
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woelen
Super Administrator
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Yep, it is true. You really have anhydrous FeCl3. I also have 100 grams of it (purchased as such) and it precisely matches the description you gave.
Congratulations  .
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12AX7
Post Harlot
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Oddly, I checked on my baggie of ferric chloride hydrate and it's turned kind of green.
The bag, which I presume is LDPE, is amazingly permeable to the HCl vapor and seems to be changing mechanical properties. It's inside a PP pill
bottle...
Tim
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Magpie
lab constructor
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Thank you Woelen for the confirmation. I have a feeling we have (or had) the same supplier. 
The FeCl3 on the watch glass continued to take up water until it was all in puddles. IIRC this is called deliquescence. Color had turned dark brown.
The original reason I bought the FeCl3 was to perform qualitative tests on organic compounds that I synthesize. My procedures for phenol and ethyl
acetoacetate both called for this test. Its very sensitive. Just a drop of the organic in about 10mL water will turn pink or purple with 2 drops of
0.5M FeCl3.
I believe this test is specific for enols. I don't know the chemistry behind the test or what the colored products are. Perhaps someone on the board
can tell me?
The single most important condition for a successful synthesis is good mixing - Nicodem
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woelen
Super Administrator
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I had my ferric chloride from a German supplier, but I think the supplier you meant is a Canadian photography raw chemical supplier, and yes, I have
purchased chemicals from that supplier also. Shipping, however, is quite expensive from there (at least, for me).
Ferric ions form a deep purple complex with phenolic compounds and a deep red complex with acetates and acetic acid.
IIRC the -OH group forms a complex with the iron (III) ion, I expect the lone pair of electrons on the O-atom to coordinate to the metal ion, just
like water does. I have done the coordination experiments, and they work great for phenol, hydroquinone, catechol, acetic acid and acetates. They do
not work for ethanol and methanol. Apparently, in the latter compounds, the lone pair of electrons in the O-atom is withdrawn too much. The
coordination of the -OH group also does not work in thymol, although that is a phenolic compound. The latter probably is due to steric hindrance.
[Edited on 2-3-07 by woelen]
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Magpie
lab constructor
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Woelen: No my supplier is US. You stated in another thread that you used to buy from them but now they won't ship out-of-country. This is just more
fallout from the War on Terror, I suppose. Too bad too, as they are cheap and ship lightning fast.
Yes, I believe I was incorrect in stating this test is enol specific. My old lab manual says it also tests positive for apha-hydroxy acids. And you
have noted others. Forming coordination compounds with an oxygen lone pair does seem like a likely mechanism.
I tested purple for the phenol, and pink for the ethyl acetoacetate.
The single most important condition for a successful synthesis is good mixing - Nicodem
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