Sciencemadness Discussion Board

Is this a potential mercuric acetate synthesis?

Ax165Xj - 31-5-2013 at 16:37

First post, thanks for your patience.
I attempted to find this answer but did not succeed, the other thread I found was regarding a synthesis starting from Hg metal.

Could Hg(SO4) be used to create Hg(Ac2) by a simple metathesis using solubility differences? The sulfate is insoluble in water but the acetate is.

Essentially, could I add an aqueous solution of Ba(Ac2) to solid Hg(SO4), producing Hg(Ac2) and BaSO4?

It seems to me a priori that this would work but I am not positive the mercuric sulfate would dissolve into solution to even participate in the reaction.

If this would not work, is there another good route from mercuric sulfate?

elementcollector1 - 31-5-2013 at 16:42

Not necessarily. A better method would be to start with a soluble mercury compound and work from there - much more likely to get a reaction.
I have no experience in mercury, but I wouldn't think a reaction between a soluble barium compound and an insoluble mercury compound would react - any equilibrium would be too far to the left.

solo - 31-5-2013 at 16:44

Reference Information



MERCURY COMPOUNDS

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Ax165Xj - 31-5-2013 at 17:43

Quote: Originally posted by solo  
Reference Information



MERCURY COMPOUNDS


Very informative, thank you.

Unfortunately the only mercury I have is the sulfate. I suppose the peracetic acid oxidation of the metal is a decent possibility.

blogfast25 - 1-6-2013 at 12:56

Quote: Originally posted by Ax165Xj  

Essentially, could I add an aqueous solution of Ba(Ac2) to solid Hg(SO4), producing Hg(Ac2) and BaSO4?

It seems to me a priori that this would work but I am not positive the mercuric sulfate would dissolve into solution to even participate in the reaction.



Essentially, yes. The extreme insolubility of BaSO4 will cause the also insoluble HgSO4 to convert. This is only true if the solubility product Ksp of BaSO4 is significantly smaller than that of HgSO4, which I'm 95 % certain is the case.

Analogous is the preparation of small amounts of KOH solution from slaked lime (poorly soluble) and potash because calcium carbonate is so insoluble:

Ca(OH)2(s) + K2CO3(aq) === > CaCO3(s) + 2 KOH(aq)

You'll need to simmer the Ba(OAc)2 and HgSO4 in stoichiometric amounts for some time, because this reaction will take time to achieve full conversion.
Quote: Originally posted by elementcollector1  
[...] but I wouldn't think a reaction between a soluble barium compound and an insoluble mercury compound would react - any equilibrium would be too far to the left.


Where the equilibrium is depends in this case very simply on the Ksp of both insoluble products: the one with lowest Ksp is the one that is formed in equilibrium conditions, provided there is of course a significant difference in Ksp.



[Edited on 1-6-2013 by blogfast25]

S.C. Wack - 1-6-2013 at 18:11

Simmering either salt or merely adding them to water will not proceed in a desirable way, due to hydrolysis.