What is the EAN of cobalt in the polynuclear carbonyl dimer ? (Atomic number of Co = 27) — Coordination Compounds Chemistry Question

💡 Solution & Explanation

Oxidation state is 0. Electrons per Co from 4 CO ligands = $4 \times 2 = 8$. The metal-metal ($Co-Co$) bond contributes 1 electron to each Co atom. $EAN = 27 - 0 + 8 + 1 = 36$.