Final answer:
The correct structure for chlorobis(ethylenediamine) nitrocobalt(III) bromide is [Co(en)2(Cl)(NO2)Br]3+, which correctly balances the charges and accounts for the ligands attached to the cobalt ion.
Step-by-step explanation:
The structure of the coordination sphere of chlorobis(ethylenediamine) nitrocobalt(III) bromide includes cobalt(III) as the central metal ion, two ethylenediamine (en) ligands, one nitro (NO2) ligand, one chloride (Cl-), and one bromide (Br-) ligand. Given the nature of the coordination complex, where cobalt has a +3 oxidation state, and ethylenediamine is a neutral bidentate ligand that coordinates through two nitrogen atoms, the correct representation of this complex is [Co(en)2(Cl)(NO2)Br]3+, as in option c. The ethylenediamine ligands are shown within the coordination sphere, indicating the direct bonding to the cobalt ion, while the charges of the ligands and the metal ion balance out to the cationic charge of 3+.