When $FeCl_3$ reacts with $K_4[Fe(CN)_6]$,which of the following compounds is formed?

Coordination compounds are of great importance in biological systems. In this context,which of the following statements is incorrect?

Dimethyl glyoxime gives a red precipitate with $Ni^{2+}$,which is used for its detection. To get this precipitate readily,the best $pH$ range is

Identify the incorrect pair.

When acetic acid and $K_4[Fe(CN)_6]$ are added to a copper salt,a chocolate precipitate is obtained of the compound:

Aqueous solution of a metallic nitrate $X$ reacts with $NH_4OH$ to form $Y$,which dissolves in excess $NH_4OH$. The resulting complex is reduced by acetaldehyde to deposit the metal. $X$ and $Y$,respectively,are