Question

While extracting an element from its ore, the ore is grind and leached with dil KCN solution to form the soluble product potassium argentocyanide. The element is
A. lead
B. chromium
C. manganese
D. silver

Answer 1

Correct Answer - D
Silver metal is extracted from the argentite ore `Ag_(2)S`. By cyanide process. In this methdo, the concentrated ore is treated with dilute solution of potassium cyanide, then a soluble complex potassium dicyanoargenate (I) is formed which when reacted with zinc, silver is extracted as a ppt.
`Ag_(2)S+4KCN to 2K[Ag (CN)_(2)]+Na_(2)S`
`2K[Ag(CN)_(2)]+Zn to K_(2)[Zn(CN)_(4)]+2Ag darr`