Verified Solution • 2025–26 Session
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QNEET-2017-Ch-933: NEET 2017 Chemistry - Class 12 NEET-2017-Ch-933 Solution: Extraction of gold and silver involves leaching with \(CN^-\)…
Extraction of gold and silver involves leaching with ion. Silver is later recovered by distillation zone refining displacement with Zn liquation
Multiple Choice Options
- A distillation
- B zone refining
- C displacement with Zn
- D liquation
Step-by-Step Verified Solution
Zn being more reactive displaces Ag and Au.
4M(s)
+ 8NaCN(aq)
+ 2H 2 O(aq)
+ O 2 (g)
_
4Na[M(CN) 2 ](aq)
+ OH(aq)
2Na[M(CN) 2 ](aq)
+ Zn(s) _ Na 2 [Zn(CN) 4 ](aq)
+2M(s)
Here M = Ag or Au
This method is known as Mac-Arthur forest cyanide
process.