Write the chemical reactions involved in the extraction of gold by cyanide process. Also give the role of zinc in the extraction.

 
NEETprep Answer:
 
i 4Aus + 8CN-aq+ 2H2Oaq+O2g 4 AuCN2-aq+ 4OH-aqii 2 AuCN2-aq+ Zns  2Aus + ZnCN42-aq
 
Zinc acts as a reducing agent in this reaction.