The metal which is extracted by oxidation and subsequent reduction from its ore is : (A) Al (B) Cu ( — JEE Mains Chemistry Past Papers Chemistry Question

💡 Solution & Explanation

In the metallurgy of silver and that of gold, the respective metal/ore is leached with a dilute solution of NaCN or KCN in the presence of air (or O2) from which the metal is obtained later by displacement with zinc scrap. So, in metallurgy of silver and gold first oxidation then reduction process is followed. 4M(s) + 8CN–(aq) + 2H2O(aq) + O2(g)  4[M(CN)2]– (aq) + 4OH–(aq) (M= Ag or Au) 2[M(CN)2]–(aq) + Zn(s)  [Zn(CN)4]2–(aq) + 2M(s)