Question

Extraction of Ag or Au is done the cyanide process and refined form of the metals are obtained at the end. Some processes are mentioned below.

(I) Leaching
(II) Reduction
(III) Complexation

Out of the given processes the one(s) which are used in the cyanide process is/are

• A. Only (I) and (III)
• B. (I), (II) and (III)
• C. Only (I) and (III)
• D. Only (II) and (III)

Answer 1

The correct option is B (I), (II) and (III)

$4M+8C{N}^{-}+2H_{2}O+O\to 4\left[M\right(CN{)}_2{]}^{-}+4O{H}^{-}$

$2\left[M\right(CN{)}_2{]}^{-}+Zn\to Zn(CN{)}_4^{2-}+2M$