Question

Gold is extracted by hydrometallurgical procees based on its property
A. of bing electropositive
B. of being less reactive
C. to form complexes which are water soluble
D. to form salts which are water soluble

Answer 1

Correct Answer - C
Hydrometallurgy is the process of dissilving the metal or its ore by the action of a suitable chemicla regent followed by recovery of the metal either by electroysis or by the use of a suitable precipitating agent.
`4Au+8KCN+2H_(0)+underset(air)(O_(2))rarr`
`4K[Au(CN)_(2)]+4KOH`
`2K[Au(CN)_(2)]+Znrarr2Au +K_(2)[Zn(CN)_(4)]`