What is the coordination number of the central metal ion in [Co(en)3]3+?

💡 Solution & Explanation

In the coordination complex [Co(en)3]3+, ethylenediamine acts as a bidentate ligand, meaning each molecule donates two electron donor pairs to the central cobalt ion. Since three bidentate ligands are attached, they contribute a total of six donor atoms, resulting in a coordination number of 6. Alternative numerical values fail to account for the bidentate nature of the ligand chelating the metal center.