(a) Write the steps involved in the extraction of pure metals in the middle of the activity series from their carbonate ores. (b) How is copper extracted from its sulphide ore? Explain the various steps supported by chemical equations. Draw labelled diagram for the electrolytic refining of copper.

(a) The steps involved in the extraction of pure metals in the middle of the activity series from their carbonate ores are: <ol> <li>Concentration of the ore: The carbonate ore is crushed and then concentrated by froth floatation process.</li> <li>Conversion of carbonate ore to oxide: The concentrated ore is then heated strongly in the absence of air to convert it into metal oxide. $$\text{ZnCO}_3 \rightarrow \text{ZnO} + \text{CO}_2$$</li> <li>Reduction of metal oxide: The metal oxide is then reduced to metal by using a suitable reducing agent such as carbon. $$\text{ZnO} + \text{C} \rightarrow \text{Zn} + \text{CO}$$</li> <li>Purification of metal: The metal obtained is then purified by electrolytic refining.</li> </ol> (b) Copper is extracted from its sulphide ore by the following steps: <ol> <li>Concentration of the ore: The sulphide ore is crushed and then concentrated by froth floatation process.</li> <li>Roasting of the ore: The concentrated ore is then roasted in a reverberatory furnace to convert it into oxide. $$2\text{Cu}_2\text{S} + 3\text{O}_2 \rightarrow 2\text{Cu}_2\text{O} + 2\text{SO}_2$$</li> <li>Reduction of metal oxide: The metal oxide is then reduced to metal by using a suitable reducing agent such as carbon. $$\text{Cu}_2\text{O} + \text{C} \rightarrow 2\text{Cu} + \text{CO}$$</li> <li>Purification of metal: The metal obtained is then purified by electrolytic refining. <br><br>

<br><br>Electrolytic refining of copper: <br><br>

<br><br>The impure copper is taken as anode and pure copper is taken as cathode. The electrolyte is a solution of copper sulphate. On passing electric current, the impure copper dissolves from the anode and pure copper is deposited at the cathode.