Why are compounds of silver (AgCl, for example) so insoluble?
Silver nitrate is quite soluble?
Yes, but silver nitrate is (close to) the only one. And if you check, just about anything nitrate is soluble. But silver isn't soluble where most other cations are. That is undeniable. Just look at silver chloride.
Sorry, but this is the only case on this forum so far where I am sure of my correctness. This and the concentration problem. A compound with silver, for the most part, is insoluble when the same anion with (almost) any other cation would be soluble.
Then why silver (I) fluoride is so much water soluble than most other fluorides (excepting those of alcaline metals)?
Why silver perchlorate is extremely water soluble?
Why silver complexes with cyanide or with ammonia are soluble?
I sincerely don't find a lot of sense in your question.
There are plenty of soluble Ag compounds. Silver is soluble as a sulfate, acetate, etc. In comparison to a Group IA metal, I suppose you would be right, it's fairly insoluble, but other than that it's really pretty normal.
To answer why some silver compounds are insoluble, it's same reason why any other compound would be insoluble. Look at the stability of the ionic bonds, relative atomic radii, charge of each ion, etc.
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