Q. Gold is extracted by hydrometallurgical process, based on its property
A) Of being electropositive
B) Of being less reactive
C) To form complexes which are water soluble
D) To form salts which are water soluble
Explanation
(b)
Hydrometallurgy is the process of dissolving the metal or its ore by the action of a suitable chemical reagent followed by recovery of the metal either by electrolysis or by the use of a suitable precipitating agent.
$4Au + 8KCN + 2H_{2}O + O_{2} \longrightarrow 4K\left\lbrack Au(CN)_{2} \right\rbrack + \ 4KOH$
air
$2K\lbrack Au(CN)_{2} + Zn \longrightarrow 2Au + K_{2}\lbrack Zn(CN)_{4}\rbrack$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.