Continuous Hydrolysis of CuCl2 in the Copper Based Thermochemical Hydrogen Cycle

[NNadir]

3. It's a shame that kids no longer get to play with chemistry sets. They're "too dangerous," all of a sudden. A minor...

...correction to your post is that if you precipitated "copper chloride," it was not CuCl₂, but CuCl, the monovalent chloride, which is analogous in its chemistry to silver (a congener of copper) which also forms insoluble monovalent halides, AgCl, AgBr, and AgI, salts involved in the discovery of photography. CuCl₂ is soluble. It is possible the experiment you performed was a reduction of CuCl₂ to CuCl, in which case the experiment you described was in fact what you did.

Interestingly, AgF is soluble, something I didn't know until I almost advised a junior scientist to use explain an analytical chemistry result and looked into it, happily, before hand.

Silver exhibits a +2 oxidation state only under extreme conditions, often involving fluorine as the oxidizing agent, although other examples are known.

(cf. Wojciech Grochala, Beyond fluorides: Extension of chemistry of divalent silver to oxo ligands, Inorganic Chemistry Communications, Volume 11, Issue 2, 2008.)

By contrast with its congener, the +2 oxidation state for copper is its most stable oxidation state.

Even more interesting is that Au, the other congener, prefers the +3 oxidation state, although it exhibits a monovalent state and although it is famously resistant to oxidation from its most stable oxidation state, zero, the metallic state, which is why alchemists in primitive times were so obsessed with it, because it was believed to contain the secret of eternal life.

It is a shame that kids no longer have interesting chemistry sets, if they have chemistry sets at all. I had one when I was a kid, and spent all of my time that I remember with it trying to make gun powder in a (thankfully) stupid way. My parents couldn't advise me because neither of them finished high school. If they had been exposed to chemistry they almost certainly would have declined to help me in the task.

A bit of irony:

As an old man, my father, became an amateur magician to put on shows for kids in hospitals, shelters and the like. Somehow got his hands of white phosphorous, and asked me about it, whereupon I freaked out that he was playing with it.

Thanks for your comment.