In which of the following complexes does exactly one chloride ligand satisfy both the primary valenc — Coordination Compounds Chemistry Question

💡 Solution & Explanation

Primary valencies are satisfied by anions (oxidation state), while secondary valencies are satisfied by ligands inside the coordination sphere. Anion ligands inside the coordination sphere satisfy BOTH primary and secondary valencies. In $[Fe(NH_3)_5Cl]Cl_2$, there is $1$ $Cl^-$ inside the coordination sphere. It acts as a ligand (satisfying secondary valency) and contributes to the oxidation state of $Fe$ (satisfying primary valency).