HollowMan
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Al/Hg reduction
Hi,
Iam looking for a explanation, how these Al/Hg reductions with acetid acid work.
I know that the used Hgcl2 is reduced to Hg at the surface of the Al pieces. So the Al2O3 is not protecting the Al anymore by contact with water. So
the H2O is reduced to H2 and the Al is oxidated to Al2O3.
The acetid acid is working as a catalyst but how does it work?
Why are some reactions working at the beginning and stopp witchout beeing able to be started again?
Usually the Al should react to Al2O3 anyway?
I got the Vogels Practical organic chemestry book where the preperation of Al/Hg reducing agent should be written down, but i couldnt find...
Would be great to get my queestions answered by someone who knowes.
Best regards
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Chemosynthesis
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I'm not sure the exact mechanism has been elucidated. It would be interesting to see if anyone can say definitively.
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HollowMan
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Why u have to use a 70% acetic acid? what happens if higher or lower concentrated and why?
doesent anyone know? or even where its located in Vogels practical org chemestry?
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macckone
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You don't actually need acetic acid.
Aluminum amalgam will react with water
without acetic acid present.
However the specific reaction may use
acetic acid to protect the product from
over reduction.
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vmelkon
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Quote: Originally posted by HollowMan  | Why u have to use a 70% acetic acid? what happens if higher or lower concentrated and why?
doesent anyone know? or even where its located in Vogels practical org chemestry? |
Well, if you were to write about what reaction you are talking about, it would help.
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HollowMan
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So the acetic acid isnt working as a catalyst? i know the reaction will take place anywhy. I thought about reducing nitropropens like 3,4
Dimethoxynitropropen
[Edited on 27-11-2014 by HollowMan]
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Nicodem
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There have been several articles on the mechanism of metal dissolving reductions posted on the forum. If you UTFSE you can find these:
https://www.sciencemadness.org/whisper/viewthread.php?tid=25...
https://www.sciencemadness.org/whisper/viewthread.php?tid=92...
... and probably others.
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unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
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