Extraction of gold and silver involves leaching the metal with CN- ion. The
metal is recovered by ________________.
(i) displacement of metal by some other metal from the complex ion.
(ii) roasting of metal complex.
(iii) calcination followed by roasting.
(iv) thermal decomposition of metal complex.
NCERT Class XII
Chemistry - Exemplar Problems
Chapter 6. General Principles and Processes of Isolation of Elements