Question
\[CuS{{O}_{4}}\left( aq. \right)\xrightarrow{{{H}_{2}}S\uparrow }M\downarrow \xrightarrow[\text{of}\,KCN]{\text{Excess}}N+O\]
Then final products $$N$$ and $$O$$ are respectively.
A.
$${\left[ {Cu{{\left( {CN} \right)}_4}} \right]^{3 - }},{\left( {CN} \right)_2}$$
B.
$$CuCN,{\left( {CN} \right)_2}$$
C.
$${\left[ {Cu{{\left( {CN} \right)}_4}} \right]^{2 - }},{\left( {CN} \right)_2}$$
D.
$$Cu{\left( {CN} \right)_2},{K_2}S$$
Answer :
$${\left[ {Cu{{\left( {CN} \right)}_4}} \right]^{3 - }},{\left( {CN} \right)_2}$$
Solution :
\[CuS{{O}_{4}}\left( aq. \right)\xrightarrow{{{H}_{2}}S}\underset{\begin{smallmatrix}
\text{Black ppt}\text{.} \\
\left( M \right)
\end{smallmatrix}}{\mathop{2CuS}}\,\xrightarrow[\text{Excess}]{KCN}{{\left[ \underset{\left( N \right)}{\mathop{Cu}}\,{{\left( CN \right)}_{4}} \right]}^{3-}}+\underset{\left( O \right)}{\mathop{{{\left( CN \right)}_{2}}}}\,\uparrow \]