Re: Copper acetate

I cannot imagine that's it. Calcium sulfate is hardly soluble in water: 0,3
grams/100 ml.. I had about 400 ml of solution so there was at most 1.5
grams. I got at least 20 grams of that precipitation!

Bas

"Uncle Al" <UncleAl0@xxxxxxxxxxxxx> schreef in bericht
news:42728910.C31C4609@xxxxxxxxxxxxxxxx
> Bas wrote:
> >
> > Hi people, I have a question about the next process I tried, and which
gave
> > me a suprisingly result.
> >
> > I've tried to make copper acetate in the following way:
> >
> > I've 'dissolved' calcium carbonate in acetic acid (household), which
gave me
> > Ca(Ch3COO)2 in solution.
> > I've boiled the solution, and let the Ca(CH3COO)2 crystallize (well..
> > crystals... an off-white stuff was the result)
> >
> > I have CuSO4 of not a very pure quality, so I dissolved this in
destilled
> > water, filtered it, and boiled again this solution, and collected the
(very
> > nice) blue crystals.
> >
> > Next step was to calculate the stoichiometric values of the reaction :
> > CuSO4.5H2O + Ca(CH3COO)2 --> CaSO4 (ppt) + Cu(CH3COO)2 ( + 5H2O).
> >
> > I assume I'm right for taking 5 molecules of water for each CuSO4
molecule,
> > everywhere I read, CuSO4 crystallizes with 5 molecules of water..right?
> >
> > I dissolved both the CuSO4.5H2O and the Ca(CH3COO)2 in distilled water
> > (seperated) and let it react in a glass beaker. After a while a white
> > precipitate was there.. the CaSO4. The solution turned into a deeper
blue,
> > somewhat green.. I think IMHO that must be due the Cu(CH3COO)2 in
solution.
> >
> > I filtered the result and obtained a clear, nice deep blue (bit green)
> > solution.
> >
> > I started to boil this solution, to obtain the Cu(CH3COO)2 in
crystals..but
> > what happened? At the time the solution started to boil a precipitate
was
> > formed! I let it go for a while and after some minutes I took the beaker
> > from the heat source and filtered.. The result was a (mint) green
> > precipitate in the filter, which really looked a LOT like CuCO3! The
> > solution has lost it typical dark blue (little greenish) color, and
looked
> > more 'pure' blue to me.
> >
> > So I suspect the Cu(CH3COO)2 decomposed..but when I looked on the
Internet,
> > I found that Copper acetate decomposes at 240 degrees Celcius! (boiling
> > point 240 degrees Celcius and decompose), so that is a lot higher
> > temperature than my boiling solution was..
> >
> > Am I correct about what I did and what happened? Has the Cu(CH3COO)2
> > decomposed, and WHY at a temperature (much) lower than 240 degrees
Celsius?
> > Or is there something else wrong?
>
> Your reagents are dirty. Calcium sulfate is a rather soluble in
> water. There are basic copper sulfates and double salts.
>
> --
> Uncle Al
> http://www.mazepath.com/uncleal/
> (Toxic URL! Unsafe for children and most mammals)
> http://www.mazepath.com/uncleal/qz.pdf


.

Relevant Pages

  • Re: Copper acetate
    ... > Bas wrote: ... At the time the solution started to boil a precipitate ... >> precipitate in the filter, which really looked a LOT like CuCO3! ...
    (sci.chem)
  • Re: Copper acetate
    ... Bas wrote: ... At the time the solution started to boil a precipitate ... > precipitate in the filter, which really looked a LOT like CuCO3! ...
    (sci.chem)
  • Re: Copper acetate
    ... > water, filtered it, and boiled again this solution, and collected the (very ... At the time the solution started to boil a precipitate was ... > precipitate in the filter, which really looked a LOT like CuCO3! ... > I found that Copper acetate decomposes at 240 degrees Celcius! ...
    (sci.chem)
  • Copper acetate
    ... At the time the solution started to boil a precipitate was ... precipitate in the filter, which really looked a LOT like CuCO3! ... I found that Copper acetate decomposes at 240 degrees Celcius! ...
    (sci.chem)
  • Re: Copper acetate
    ... just read the original post - CaSO4 as numbers suggest is very probably a primary component... ... After a while a white precipitate was there.. ... The result was a green precipitate in the filter, which really looked a LOT like CuCO3! ... I found that Copper acetate decomposes at 240 degrees Celcius! ...
    (sci.chem)