Extraction of gold and silver involves leaching with CN-ion. Silver is later recovered by

Extraction of gold and silver involves leaching the metal with CN- and the metals silver and gold are later recovered by displacement method eith high electropositive metals.4M(s)+8CN(aq)-+2H2O(aq)+O2(g)⟶4M(CN)2(aq)-+4OH(aq)- 2M(CN)2(aq)-+Zn(s)⟶2M(s)+Zn(CN)4(aq)2-