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Crypto
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This would actually be a pretty cool method of producing Al ethoxide or methoxide, but wouldn't it react with CuCl2 if more, than a small amount would
be present?
Are there any other solvents in which copper chloride is soluble? I could only find info about methanol, ethanol and acetone.
[Edited on 23-12-2013 by Crypto]
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DraconicAcid
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Because copper salts are acidic.
Hydrated copper ions can lose H+ ions.
Cu(H2O)62+ + H2O -> Cu(H2O)5(OH)+ + H3O+.
The reaction of the zinc with the hydronium ion happens along with the reaction of the zinc with the copper ions.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Random
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Quote: Originally posted by Crypto  | This would actually be a pretty cool method of producing Al ethoxide or methoxide, but wouldn't it react with CuCl2 if more, than a small amount would
be present?
Are there any other solvents in which copper chloride is soluble? I could only find info about methanol, ethanol and acetone.
[Edited on 23-12-2013 by Crypto] |
CuCl2 would be preferably anhydrous along with anhydrous alcohol and only a small amount would be used to remove protective layer of Al oxide. Al will
react with anhydrous alcohol after that like any very reactive metal.
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Crypto
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| Quote: |
CuCl2 would be preferably anhydrous along with anhydrous alcohol and only a small amount would be used to remove protective layer of Al oxide. Al will
react with anhydrous alcohol after that like any very reactive metal. |
I understand, but what if one would add more CuCl2 ? Would it react with the ethoxide?
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DraconicAcid
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Aluminum will preferentially react with copper(II) ions over alcohol, surely.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Crypto
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| Quote: |
Aluminum will preferentially react with copper(II) ions over alcohol, surely. |
Forming anhydrous AlCl3 ? That would be an easy way to obtain it. No need for high temperatures and HCl or Cl gas...
I'll definitely do some experimenting when I'll get back from holidays 
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DraconicAcid
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| Quote: Originally posted by Crypto |
| Quote: |
Aluminum will preferentially react with copper(II) ions over alcohol, surely. |
Forming anhydrous AlCl3 ? That would be an easy way to obtain it. No need for high temperatures and HCl or Cl gas...
I'll definitely do some experimenting when I'll get back from holidays
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Your alcohol would have to be absolutely dry, and you would probably still get solvated AlCl3 rather than anhydrous. You might find that
heating it to drive off the alcohol gives decomposition rather than nice anhydrous AlCl3.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Crypto
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I was thinking about using methanol. My chem supply shop has 99.9% one. At least they state so  Not only dry but also has a pretty low boiling point so I want to give it a try. Of course I'm not arguing about
getting anhydrous AlCl3 that way, because something tells me you're right.
I'll experiment anyway 
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macckone
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Aluminum Chloride forms complexes with methanol, ethanol and acetone. If you are trying for a Friedel-Crafts catalyst, this won't work because of the
complex.
It is possible that a small amount of CuCl2 would cause aluminum to react creating the methoxide or ethoxide but I don't have a reference.
Mercuric Chloride definitely causes that to happen.
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Crypto
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| Quote: |
It is possible that a small amount of CuCl2 would cause aluminum to react creating the methoxide or ethoxide but I don't have a reference. Mercuric
Chloride definitely causes that to happen. |
Mercuric Chloride, Gallium and Iodine, all of them being expensive and kinda hard to get. Even thou only a small ammount is needed, CuCl2 would be a
nice alternative if it works...
Does Al react with DCM?
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Random
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AlCl3 would probably be producing some ethyl chloride along the way, depends on the conditions in solution. Basic conditions among alkoxides wouldn't
promote it as much as acidic conditions. CuCl2 is soluble like 53g/100mL alcohol thsts significant iirc. Maybe i'm wrong though.
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macckone
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I am not sure what the reactivity would be but Al is generally incompatible with chlorinated compounds from a long term
perspective. I don't know that it would react under normal
conditions over a short period of time. With heat and abrasion
to remove the oxide coating it would likely react. Various
impurities in the aluminum and the DCM would change
the reactivity (water in particular). Any aluminum chloride
formed would likely accelerate the reaction.
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WGTR
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If there are aromatic hydrocarbons present in the DCM, then a pretty vigorous thermal runaway can occur in the presence of
aluminum or iron:
http://patentimages.storage.googleapis.com/pages/US3646229-0...
http://patentimages.storage.googleapis.com/pages/US3646229-1...
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blogfast25
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| Quote: Originally posted by macckone |
I am not sure what the reactivity would be but Al is generally incompatible with chlorinated compounds from a long term
perspective. |
There's a very long thread by 'peach' (on SM) on an attempt to chlorinate Al with dry HCl using dichloromethane (DCM) as a solvent (all done at RT).
In my opinion the experiment failed but it did show that DCM shows no significant reactivity towards DCM.
I see the quest for anh. AlCl3 continues, as usual w/o much success.
There's a lab preparation that involves a dichloroalkane, iodine and Al powder (IIRW). I'll see if I can dig it up.
Edit:
Here the link to the Al/DCM/HCl thread:
http://www.sciencemadness.org/talk/viewthread.php?tid=14111&...
The post by ‘rrks’ on 26-7-2010 links to a *pdf which still works. Basically the reaction advocated is:
Al + 3/2 I2 + 3 CH2Cl2 === > AlCl3 + 3 CH2ICl
In strictly anhydrous conditions this yields anh. AlCl3, acc. to the author.
[Edited on 26-12-2013 by blogfast25]
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blargish
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Referring to one of the earlier points made...
| Quote: Originally posted by bismuthate | | That was the conclusion I came to but then I wondered where the Al(OH)3 went. My theory is that it reacts with CuCl to form Cu(OH)2 which then
decomposes to CuO. Although I've only seen a video of it being lit on fire (I can't seem to find it) so I'll need to test it myself.
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I may be wrong (let me know if I am) but I believe the absence of Al(OH)3 may be due to the formation of tetrachloroaluminate as a side
product in the reaction instead. First the Al2O3 layer on the Al is dissolved due to the presence of chloride ions (forming
tetrachloroaluminate) via the following equation.
Al2O3 + 8Cl- + 3H2O --> 2AlCl4- + 6OH-
The freshly exposed Al reacts with water to form more aluminum oxide (and hydrogen gas)...
2Al + 3H2O --> Al2O3 + 3H2
Now what I think happens is that this process cycles along as a side reaction as the normal reaction between CuCl2 and Al is taking place
Hydroxoaluminate may be formed as well in a side reaction along with the tetrachloroaluminate as the solution becomes more basic. (I'm not too sure
about this though)
Al2O3 + 3H2O + 2OH- --> 2Al(OH)4-
Both of these reactions could account for the absence of a precipitate of Al(OH)3 as I believe that both hydroxoaluminate and
tetrachloroaluminate are soluble in water.
I have yet to test whether my assumptions are correct so this is hypothetical
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Random
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something is missing because this doesn't occur in neutral conditions which in this equation probably are ( no H+ or OH- ion presence)
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blogfast25
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Nope. That doesn't happen to any appreciable degree.
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