NTA Abhyas NEET2020ChemistryGeneral Principles and Processes of Isolation of MetalsPractice
Gold is extracted by making soluble cyanide complex. The cyanide complex is
Options
- A[ A u ( C N ) 4 ] -
- B[ A u ( C N ) 2 ] -
- C[ A u ( C N ) 3 ] -
- D[ A u ( C N ) ] -
Correct answer
B. [ A u ( C N ) 2 ] -
Step-by-step solution
Gold is extracted by making soluble cyanide complex. The cyanide complex is [ A u ( C N ) 2 ] - 4 A u + 8 C N - + 2 H 2 O + O 2 → 4 [ A u ( C N ) 2 ] - + 4 O H - The metal is recovered by reduction with zinc. 2 [ A u ( C N ) 2 ] - + Z n → [ Z n ( C N ) 4 ] 2 - + 2 A u