(I). 3CuO(s) + 2NH3(g) -----> 3Cu(s) + 3H2O(l) + N2(g) 
(II). 2NH3(g) + 3Cl2(g) -----> 6HCl(g) + N2(g) 
(III). 4NH3(g) + 3O2(g) -----> 6H2O(l) + N2(g) 
The reactions represented by the equations above demonstrate the