Solution: Isolation of Group 8B(10) elements, used as industrial catalysts, involves a series of steps. For nickel, the sulfide ore is roasted in air: Ni3S2(s) + O2(g) ⇌ NiO(s) + SO2(g). The metal oxide is reduced by the H2 in water gas (CO + H 2) to impure Ni: NiO(s) + H2(g) ⇌ Ni(s) + H2O(g). The CO in water gas then reacts with the metal in the Mond process to form gaseous nickel carbonyl, Ni(s) + CO(g) ⇌ Ni(CO)4(g), which is subsequently decomposed to the metal.(a) Balance each of the three steps, and obtain an overall balanced equation for the conversion of Ni3S2 to Ni(CO)4.