Consider the following metallurgical processes :<br>(I) Heating impure metal with CO and distilling — Metallurgy and Isolation of Elements Chemistry Question
Question
Consider the following metallurgical processes :<br>(I) Heating impure metal with CO and distilling the resulting volatile carbonyl (b.p. 43°C) and finally decomposition at 150°-200°C to get the pure metal<br>(II) Heating the sulphide ore in air until a part is converted to oxide and then further heating in the absence of air to let the oxide react with unchanged metal sulphide<br>(III) Electrolysis of the molten electrolyte containing approximately equal amounts of the metal chloride and NaCl to obtained the metal<br>The processes used for obtaining magnesium, nickel and copper are respectively :
💡 Solution & Explanation
(I) Ni (impure) + 4CO $\xrightarrow{50^\circ C}$ [Ni(CO)4] (volatile) $\xrightarrow{230^\circ C}$ Ni (pure) + 4CO$\uparrow$<br>(II) Cu2S + 3/2 O2 $\xrightarrow{\Delta}$ Cu2O + SO2; Cu2S + 2Cu2O $\xrightarrow{\text{high temp.}}$ 6Cu + SO2<br>(III) MgCl2(s) $\xrightarrow{\text{electrolysis}}$ Mg2+(l) + 2Cl-(l); At cathode : Mg2+ + 2e- $\rightarrow$ Mg(s); At anode : 2Cl-(l) $\rightarrow$ Cl2(g) + 2e-