answer to name a complex we start by working out the oxidation number of the central metal atom and then add the names of the ligands in alphabetical order a the complex has two anionic ligands cl- four neutral ligands nh3 and an overall charge of +2 hence the oxidation number of platinum must be +4.according to the alphabetical order rules the name of the complex is tetraamminedichlorido-platinum. b the ligands co and pyridine are neutral so the oxidation number of nickel must be o if follows that the name of the complex is tricarbonylpyridinenickel o. this omplex contains the hexadented edta 4- ion as the sole ligand.The four negative charges of the ligand result in a complex with a single negative charge if the central metal ion is Cr3+. The complex is therefore ethylenediaminetetraacetatochromate(III).(d) this complex contains two anionic chloride ligands and two neutral en ligands.the overall charge of +1 must be the result of the cobalt having oxidation number +3. The complex is therefore dichloridobis(ethylenediamine)cobalt(III).(e) this complex contains two anionic I- (iodio) ligands and two neutral CO ligands. The overall charge of -1 must be the result of the rhodium having oxidation number +1. The complex is therefore dicarbonyldiiodidorhodate(I).