Chemistry - Complete d-block Question with Solution | TestHub

With ammonium solution,$\mathrm{C}\mathrm{u}\mathrm{S}{\mathrm{O}}_4$forms a stable blue complex. First it forms a precipitate of$\mathrm{C}\mathrm{u}(\mathrm{O}\mathrm{H}{)}_2$which dissolves in excess of ammonia solution forming a deep blue coloured complex.
$\mathrm{C}\mathrm{u}\mathrm{S}{\mathrm{O}}_4+2\mathrm{N}{\mathrm{H}}_4\mathrm{O}\mathrm{H}\to \mathrm{C}\mathrm{u}(\mathrm{O}\mathrm{H}{)}_2+(\mathrm{N}{\mathrm{H}}_4{)}_2\mathrm{S}{\mathrm{O}}_4$
$\text{Cu}{(\text{OH})}_2+2{\text{NH}}_4\text{OH}+{({\text{NH}}_4)}_2{\text{SO}}_4\to \underset{\text{Tetraamminecupricsulphate}}{\text{Cu}{({\text{NH}}_3)}_4{\text{SO}}_4+4{\text{H}}_2\text{O}}$