Question 19 Which of the following is an example of a hydrometallurgical process? Al2O3.nH2O(s) + 2OH(aq) + 2 H2O(1) 2 Al(OH)4 (aq) CuSO4.5H2O(s) + H2O(1) CuS(s) + H2SO4(aq) +5 OH(aq) Al(OH)3(s) + SIO2 (s) heat AISIO3(s) + 3 H2O(g) 2 Al(OH)3(s) heat Al2O3(s) + 3 H2O(g) Ni(OH)2(s) heat NiO(s) + H2O(g)