Re: Soluble catalyst that decompose H2O2

Firstly, a friendly warning regarding any experiments especially those at 
home.  Always avoid arbitrary combination of chemicals... you cannot 
predict the outcome.  As you found out in this case, a reaction can be 
quite violent.  Always investigate the potential for exothermicity, 
generation of toxic or noxious gases etc.  Always proceed with caution and 
do not forget personal protection (safety glasses for example).

Back to your question:

The vigorous exotherm you observed was the rapid decompostion of hydrogen 
peroxide into water and oxygen;

2H2O2 -> 2H2O + O2

This reaction has a whopping DeltaH (enthalpy change) of -99 kJ per mole.  
The negative sign is the cinvention used to indicate evolution of heat, 
that is an exothermic reaction.

The decomposition was catalyzed by the presence of metal ions (copper 
sulphate in aqueous solution).  It is doubtful that any surprising new 
compound was created, and evaporating the liquid merely reformed the 
original constituents, albeit in admixture.  The decomposition of hydrogen 
peroxide is catalyzed just as well by many solid surfaces as ions in 
solution, for example iron oxide (rust) and manganese dioxide being the 
most commonly cited cases.  I suspect that copper sulphate has similar 
propeties based on your observation.  It is doubtful that any "exchange " 
of ions took place... perhaps you were anticipating that chloride anions 
would form ligands to the copper and replace some water molecules.  It all 
depends on the relative concentrations as to the exact species present, 
and copper chloride complexes tend not to be formed, unless precipitated 
by the presence of large cations.

The reaction rate would of course naturally slow as hydrogen peroxide was 
"consumed" as the reaction progressed.  This is the case with all 
reactions where reactants are not replenished.  You should consult a good 
undergraduate chemistry text, and look up "reaction order" and "reaction 
rate constants"

Bibliography:
I consulted "Advanced Inorganic Chemistry" by F.Albert Cotton & Geoffrey 
Wilkinson.

You can even find some references to other reactions of hydrogen peroxide, 
including the catalyzed decomposition, in MadSci Network 
ARCHIVES (you can even learn about rocket engines!)

If you are interested to learn more about hydrogen peroxide, I suggest 
visiting the web site http://www.h2o2.com.

Thanks for your questions.

STAY SAFE!