Extraction of gold (Au) involves the formatio | vedclass

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(A) In the extraction of gold, the metal is leached with a dilute solution of $NaCN$ in the presence of air (oxygen) to form the complex $X = [Au(CN)_

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$[Au(CN)_2]^-$ and $[Zn(CN)_4]^{2-}$

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(A) In the extraction of gold, the metal is leached with a dilute solution of $NaCN$ in the presence of air (oxygen) to form the complex $X = [Au(CN)_2]^-$.Then, gold is recovered by displacement with zinc, which forms the complex $Y = [Zn(CN)_4]^{2-}$.The chemical equations are:$4Au + 8CN^- + 2H_2O + O_2 \rightarrow 4[Au(CN)_2]^- + 4OH^-$$2[Au(CN)_2]^- + Zn \rightarrow [Zn(CN)_4]^{2-} + 2Au$Thus, $X$ is $[Au(CN)_2]^-$ and $Y$ is $[Zn(CN)_4]^{2-}$.

Extraction of gold $(Au)$ involves the formation of complex ions $X$ and $Y$ as shown in the reaction: $\text{Gold ore}$ $\xrightarrow{CN^-, H_2O, O_2} HO^- + X$ $\xrightarrow{Zn} Y + Au$. $X$ and $Y$ respectively are:

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