$PCl_5$ reacts with finely divided silver on heating and a white silver salt is obtained,which dissolves on adding excess aqueous $NH_3$ solution. Write the reactions involved to explain what happens.

$A$ blood red colour is obtained when ferric chloride solution reacts with

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:

Which of the following complexes is used as an anticancer agent?

The formation of a coordination compound can be detected by $............$.

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