A) Argentite
B) Copper pyrite
C) Cinnabar
D) Galena
Correct Answer: A
Solution :
[a] In this process, the finely divided powdered argentite or the native silver or gold is treated with a dilute solution (0.5%) of sodium or potassium cyanide while a current of air is continuously passed. As a result silver ores pass into solution forming their respective soluble complex cyanides while the impurities remain unaffected which are filtered off. \[4Ag+8NaCN+{{O}_{2}}+2{{H}_{2}}O\to 4Na[Ag{{(CN)}_{2}}]+4NaOH\]Or \[A{{g}_{2}}S+4NaCN\to \underset{\text{sodium}\,\,\text{dicyano}\,\text{argentate(I)}}{\mathop{2Na[Ag{{(CN)}_{2}}]}}\,+N{{a}_{2}}S\]You need to login to perform this action.
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