Chemophiliac
Harmless
Posts: 18
Registered: 1-6-2007
Location: Connecticut, USA
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Mood: In the mood for some chemistry!!
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Synthesis of an artificial analogue of a molybdenum mineral
I am trying to synthesize artificial Szenicsite and Lindgrenite in a laboratory, but I do not know how to do this. Szenicsite is Cu3(MoO4)2(OH)4 and
Lindgrenite is Cu3(MoO4)2(OH)2
I managed to synthesize CuMoO4 as a starting point by reacting 2g of anhydrous CuCl2 with 3.1g anhydrous Na2MoO4, both placed in boiling water. I
obtained about 2.7g CuMoO4 (theoretical yield is 3.32g). It reacted as follows-
CuCl2 + Na2MoO4 -----Heat----> CuMoO4 (s) + 2 NaCl (aq)
I then filtered and dried in a crucible to yield a dry powder of "pea soup" green CuMoO4
Today, I made another batch of the stuff (same masses of reactants), but after preparing the molybdate, I reacted it with 1.19g NaOH, 2g more CuCl2
(anhydrous), and 3.1g more Na2MoO4 intending to synthesize Lindgrenite. I added the NaOH to the boiling solution of precipitated Cu Molybdate and
water. It then turned black, yielding CuO. Then I added the CuCl2 and Na2MoO4 andstirred. The solution then turned "pea soup" green again but there
was obviously a lot more molybdate precipitating out. I originally intended to synthesize Lindgrenite, but I think I just got a lot more Cu Molybdate.
Here's the reaction that I thought would produce my Lindgrenite .but alas, chemicals are fickle creatures and it didn't work (or so I think)-
CuMoO4 +2NaOH + 2 CuCl2 + NaMoO4 -----heat----> Cu3(MoO4)2(OH)2 (s) + 4 NaCl (aq)
Here's what happened in reality-
CuMoO4 + 4 NaCl (in solution from synthesis of CuMoO4)+ 2NaOH---heat---> CuO +MoO3 + Na2O (aq) + H2O
which I then added CuCl2 and NaMoO4 to-
CuO +MoO3 + Na2O (aq) + H2O + 2 CuCl2 + NaMoO4 -------> 2 CuMoO4 + CuCl2 (aq) + 6NaCl
How could I go about synthesizing Lindgrenite and Szenicsite succesfully?
Thanks!
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not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
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Mood: No Mood
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I suspected that this would have to be done by hydrothermal methods, and a search suggests this is true
Hydrothermal synthesis of lindgrenite
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi...
attached
Influence of 2-aminopyridine on the formation of molybdates under hydrothermal conditions
[Edited on 15-6-2007 by not_important]
Attachment: EJIC2005a.pdf (293kB) This file has been downloaded 509 times
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