Explain the steps involved in the extraction of metals of medium reactivity from their carbonate and sulphide ores. Supp

Question

Explain the steps involved in the extraction of metals of medium reactivity from their carbonate and sulphide ores. Support your answer with balanced chemical equations. Additionally, explain the process of electrolytic refining of impure copper with a step-by-step description and electrode reactions.

Accepted Answer

Extraction of Metals of Medium Reactivity
Metals in the middle of the activity series (such as Zinc, Iron, Lead, and Copper) are moderately reactive. They usually occur as sulphides or carbonates in nature. It is easier to obtain a metal from its oxide than from its sulphide or carbonate. Therefore, before reduction, the ore must be converted into metal oxide. Conversion of Ore into Metal Oxide: Roasting (for Sulphide Ores): The sulphide ore is converted into oxide by heating it strongly in the presence of excess air. $$	ext{Equation: } 2ZnS(s) + 3O2(g) \xrightarrow{\Delta} 2ZnO(s) + 2SO2(g)$$ Calcination (for Carbonate Ores): The carbonate ore is converted into oxide by heating it strongly in limited air or in the absence of air. $$	ext{Equation: } ZnCO3(s) \xrightarrow{\Delta} ZnO(s) + CO2(g)$$ Reduction of Metal Oxide to Metal:
The metal oxides are reduced to free metals by using suitable reducing agents such as carbon (coke) or highly reactive metals like aluminium. $$	ext{Equation: } ZnO(s) + C(s) ightarrow Zn(s) + CO(g)$$ --- Electrolytic Refining of Copper
The metal obtained by reduction is impure and needs to be refined electrolytically. Apparatus Setup: Anode: A thick block of impure copper metal. Cathode: A thin strip of pure copper metal. Electrolyte: Acidified copper sulphate ($CuSO4$) solution. Working Mechanism: On passing electric current through the electrolyte, pure copper from the anode dissolves into the electrolyte, and an equivalent amount of pure copper from the electrolyte gets deposited on the cathode. Electrode Reactions: At Anode (Oxidation): $Cu(s) 	ext{ (impure)} ightarrow Cu^{2+}(aq) + 2e^-$ At Cathode (Reduction): $Cu^{2+}(aq) + 2e^- ightarrow Cu(s) 	ext{ (pure)}$ Anode Mud: Soluble impurities go into the solution, while insoluble impurities settle down at the bottom of the anode and are known as anode mud.

Metals and Non-metals

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