The complex formed by carbon monoxide with hemoglobin is called .....

If a didentate ligand ethane-$1, 2$-diamine is progressively added in the molar ratio $en : Ni :: 1: 1, 2: 1, 3: 1$ to $[Ni(H_2O)_6]^{2+}$ aqueous solution,the following coordination entities are formed:
$I$. $[Ni(H_2O)_4en]^{2+}_{(aq)} -$ pale blue
$II$. $[Ni(H_2O)_2(en)_2]^{2+}_{(aq)} -$ blue/purple
$III$. $[Ni(en)_3]^{2+}_{(aq)} -$ violet
The wavelengths in $nm$ of light absorbed in the case of $I$ and $III$ are respectively:

The metal present in $Vitamin \ B_{12}$ is

In any ferric salt,on adding potassium ferrocyanide,a Prussian blue colour is obtained,which is:

The electrolytes usually used in the electroplating of gold and silver,respectively,are

The complex used as an anticancer agent is