What is the IUPAC name of the complex [Co(en)2Cl2]Cl?
Correct: B
The IUPAC name is Bis(ethylenediamine)dichlorocobalt(III) chloride. 'en' stands for ethylenediamine. The oxidation state of Cobalt is +3 (x + 0 + (-2) = +1, so x=3). The ligands are named alphabetically before the metal.