Q20 / 90 · KVPY 2011 (SB/SX) · Chemistry
Extraction of silver is achieved by initial complexation of the ore (Argentite) with $X$ followed by reduction with Y. $X$ and $Y$ respectively are
- Correct answerA$\mathrm{CN}^{-}$and $\mathrm{Zn}$
- B$\mathrm{Br}^{-}$and $\mathrm{Zn}$
- C$\mathrm{Cl}^{-}$and $\mathrm{Zn}$
- DNone of these
Solution
Complexation step
$\begin{array}{r}
\mathrm{Ag}_{2} \mathrm{~S}+\mathrm{CN}^{\varsigma} \rightarrow\left[\mathrm{Ag}(\mathrm{CN})_{2}\right]^{-}+\mathrm{S}^{-2} \\
\downarrow+\mathrm{Zn} \text { Reduction step } \\
{\left[\mathrm{Zn}(\mathrm{CN})_{4}\right]^{-2}+\mathrm{Ag}}
\end{array}$
Hence, the correct answer is option: 'A'.