Extraction of gold and silver involves leachi | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The extraction of gold and silver involves the formation of a soluble complex with $CN^{-}$ ions in the presence of air $(O_2)$.$4Au(s) + 8CN^{-}(

Vedclass · Accepted Answer

Displacement of metal by some other metal from the complex ion

Vedclass · Answer

(A) The extraction of gold and silver involves the formation of a soluble complex with $CN^{-}$ ions in the presence of air $(O_2)$.$4Au(s) + 8CN^{-}(aq) + 2H_2O(aq) + O_2(g) \rightarrow 4[Au(CN)_2]^{-}(aq) + 4OH^{-}(aq)$$2Ag(s) + 4CN^{-}(aq) + 2H_2O(aq) + O_2(g) \rightarrow 2[Ag(CN)_2]^{-}(aq) + 4OH^{-}(aq)$The metal is then recovered from the complex by displacement using a more electropositive metal like zinc $(Zn)$:$2[Au(CN)_2]^{-}(aq) + Zn(s) \rightarrow [Zn(CN)_4]^{2-}(aq) + 2Au(s)$$2[Ag(CN)_2]^{-}(aq) + Zn(s) \rightarrow [Zn(CN)_4]^{2-}(aq) + 2Ag(s)$Thus,the correct method is the displacement of the metal by some other metal from the complex ion.

Extraction of gold and silver involves leaching the metal with $CN^{-}$ ion. The metal is recovered by . . . . . .

Similar Questions

In which metallurgical process is the metal obtained in the molten state?

Smelting is carried out in a ...... .

Low grade $Cu$ ores are available and $Zn$ and $Fe$ scraps are also available. Which scrap among the two would be more suitable for reducing the leached $Cu$ ore (economically)?

In the extraction of which of the following,a complex ion is formed?

Which metals are extracted using the self-reduction method?

Vedclass Test Series

Exam Paper Generator

Online Exam Module