Chemistry - Coordination Chemistry Question with Solution | TestHub

Both$\mathrm{C}{\mathrm{u}}^{2+}$and$\mathrm{F}{\mathrm{e}}^{3+}$are detected by potassium ferrocyanide

$2\mathrm{C}\mathrm{u}\mathrm{S}{\mathrm{O}}_4+{\mathrm{K}}_4\left[\mathrm{F}\mathrm{e}{\left(\mathrm{C}\mathrm{N}\right)}_6\right]\to \underset{\mathrm{C}\mathrm{h}\mathrm{o}\mathrm{c}\mathrm{o}\mathrm{l}\mathrm{a}\mathrm{t}\mathrm{e}\text{ ppt.}}{\mathrm{C}{\mathrm{u}}_2\left[\mathrm{F}\mathrm{e}{\left(\mathrm{C}\mathrm{N}\right)}_6\right]}\mathrm{ }+2{\mathrm{K}}_2\mathrm{S}{\mathrm{O}}_4$

${\text{4FeCl}}_{\text{3}}\text{+}{\text{3K}}_{\text{4}}\left[\text{Fe}{\left(\text{CN}\right)}_{\text{6}}\right]\to \underset{\underset{}{\begin{array}{l}\text{Ferri-ferrocyanide}\\ \left(\text{Prussian}\text{blue}\right)\end{array}}}{{\text{Fe}}_{\text{4}}{\left[\text{Fe}{\left(\text{CN}\right)}_{\text{6}}\right]}_{\text{3}}}\text{+12KCI}$