Chemistry - Ionic Equilibrium Question with Solution | TestHub

Zinc and aluminium hydroxides are amphoteric. In excess base they form soluble zincate and aluminate species, for example $[\mathrm{Zn}(\mathrm{OH}{)}_4{]}^{2-}$ and $[\mathrm{Al}(\mathrm{OH}{)}_4{]}^{-}$. Iron(III) and nickel(II) hydroxides do not dissolve in ordinary excess aqueous sodium hydroxide.