Can ammonium salts react with insoluble bases, such as copper(II) oxide?

Can ammonium salts react with insoluble bases, such as copper(II) oxide? Textbooks and preliminary searches on Google all yield answers that give reaction of ammonium salts with strong alkalis instead.




Ammonium salts act due hydrolysis as very weak acids:


$$\ce{NH4+(aq) <<=> NH3(aq) + H+(aq)}\tag{R1}$$


and as such can dissolve such bases:


$$\ce{2 H+(aq) + CuO(s) -> H2O(l) + Cu^2+(aq)}\tag{R2}$$


The above process can be somewhat supported by copper ions affinity to ammonia (for $n = 0\mathrel{..}3$):


$$\ce{[Cu(NH3)\_n]^2+(aq) + NH3(aq) <=> [Cu(NH3)\_{n+1}]^2+(aq)}\tag{R3}$$


In contrary to my original thought, it happens in considerably extent, as Wikipedia explicitly states (I have overlooked it before) it is soluble in ammonium chloride (credit to Oscar Lanzi to point it out).


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[Wikipedia](https://en.wikipedia.org/wiki/Copper(II)_oxide) shows that copper(II) oxide is soluble in ammonium chloride solution. In this respect it resembles metal(II) oxides of magnesium, manganese and zinc.


Dissolution of such oxides can occur by either of two mechanisms. With magnesium oxide and, to a lesser extent, manganese oxide, the oxide is a strong enough base to react with ammonium ions to bring the metal ions into solution and leave a mixture of $\ce{NH3}$ and $\ce{NH4^+}$ in the solution at equilibrium. The solution with this mixture of ammonia and ammonium ions is then slightly alkaline with the $\mathrm{pH}$ in the ammonium/ammonia buffer range. Copper and zinc oxides, instead, rely on forming a complex with the ammonia, leaving essentially this complex plus $\ce{NH4^+}$ ions in a solution that remains acidic.


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