[Timothy]

When copper(II) sulphate pentahydrate is dissolved in water and added to potassium oxalate hydrate that is also dissolved in water, copper oxalate is formed and K2SO4 and H2O is also formed, I think. Does anybody know what is formed for this mechanism or what the mechanism is itself.

Thanks

[BluRay]

Which do you think are the relative solubilities?

[Timothy]

I think that the products are K2SO4 and CuC2O4 as well as H2O. The overall equation would be CuSO4.5H2O + K2C2O4.H2O = CuC2O4 + K2SO4 + H20. However when I checked this on an online chemical equation balancer, it said it was an impossible equation. I have checked in my first year chemistry manual and it said that K2SO4 is soluble. That is why it is easy to only have CuC2O4 when filtered off but it seems my products are not correct.

[BluRay]

You only have to correct the number of water molecules produced by the reaction, for the rest it's correct (the reaction happens because CuSO₄ and K₂C₂O₄ are both water soluble, while CuC₂O₄ is not).

[Timothy]

Thanks for the help.

I have got another question regarding both the CuSO4.5H2O and K2C2O4.H2O. When they are dissolved in water, since the waters attached to the molecules, they are waters of crystallization. How do these complex compounds dissolve in water. I have looked at many web pages and people either say they partially get Cu(H2O)4 2+ + SO4= while others say the answer is Cu2+ and SO42- ions. Which is correct?
Thanks

[Borek]

Copper is always complexed, either by water or by some other ligands. Water - in water solutions - is usually ignored, but if not for the ligand presence copper solution wouldn't be blue.

[Timothy]

Hi Borek

Ok, that makes sense, so when when copper(II) Sulphate pentahydrate is added to water, the copper sulphate retains it waters of hydration. If what I am saying is correct, when added to another solution which contains potassium oxalate hydrate solution, Copper oxalate, potassium sulphate and water is produced? How would you write that in an equation? Thanks

[Borek]

This is more like copper, not copper sulfate, retains its water of hydration. And not necesarilly all 5 molecules of water are bonded with copper. In the case of potassium oxalate water just goes directly into solution.

[Timothy]

I dont quite understand, when copper(II) sulphate pentahydrate is added to water, what are the products?

[Timothy]

Does anybody have a possible answer to my problem, any help will be greatly appreciated, I have to hand my write up in on the 15 March 2010. Thanks

[Borek]

I am not really sure what your problem is. The reaction equation that you gave earlier is generally OK on some level, I have no idea what level of details you need (and I am not able to give much more detailed answer without browsing my books). It can be balanced for sure.

[BluRay]

I dont quite understand, when copper(II) sulphate pentahydrate is added to water, what are the products?

CuSO₄.5H₂O + water     Cu(H₂O)₄²⁺ + SO₄^2- + H₂O

[Timothy]

Hi BluRay and Borek

Thanks for all the help, I was able to get the work done.

Thanks again