Chemistry - Coordination Chemistry Question with Solution | TestHub

The correct options are A and B.

A. Tris($\mu$-tetraammine-$\mu$-dihydroxidocobalt(III)) ion: This is a trinuclear complex. Each of the three cobalt centers is bonded to four ammonia ligands and two bridging hydroxido ligands. The total Co-N coordinate bonds are $3\times 4=12$.

B. ($\mu$-Amido-$\mu$-hydroxido)-bis(tetraamminecobalt(III)) ion: This is a dinuclear complex. Each cobalt center is bonded to four ammonia ligands and one amido. The total Co-N coordinate bonds are 10.

C. Acetyldicarbonyliodido-bis(trimethylphosphine)iron(II): The acetyl ligand has one Fe-C bond. The two carbonyl ligands each have one Fe-C bond. Total Fe-C bonds = $1+2=3$.

D. Dichloro(ethylenediaminetetraacetato-N,O)palladate(II) ion: Ethylenediaminetetraacetate (EDTA) is a hexadentate ligand. When it coordinates through N and O atoms, it forms 5 chelate rings. However, the complex name specifies coordination through N and O, implying not all donor atoms are used, which would reduce the number of chelate rings. If it were fully hexadentate, it would form 5 chelate rings. The question implies a specific coordination mode. If it coordinates as a tetradentate ligand (2N, 2O), it would form 3 chelate rings. The option states 5, which is only true if EDTA acts as a hexadentate ligand.