In my Inorganic chemistry lab we're studying how Cu(II) behaves in aqueous solution.
We added NaOH to a solution of CuSO4 and we saw a blue precipitate of Cu(OH)2. The thing is, our professor told us that if we kept adding base to our solution of CuSO4, we would be able to see how Cu(OH)2 was redissolved and the species Cu(OH)4 and (Cu(OH)6 soluble in water, but we didn't see it. (we didn´t see any change at all)
Maybe the base we added wasn´t too concentrated?
I searched in lots of forums for this specific thing and nothing appeared, so if anyone tried this experiment and knows why, it would be much helpful.