Consider the following two carbonyl compounds (i) [Tc(CO)6]^+ and (ii) [Nb(CO)6]^- . Select incorrec — Coordination Compounds Chemistry Question

💡 Solution & Explanation

Step 1: Metal carbonyls are highly stable when the central metal atom achieves the Effective Atomic Number (EAN) of the next noble gas (for the 3d transition series, Krypton with EAN = 36). Step 2: Calculate the EAN of Mn in Mn(CO)5: 25 (atomic number of Mn) - 0 + 2 * 5 = 35. Step 3: Because Mn(CO)5 is one electron short of the stable EAN of 36, it has a strong tendency to accept one electron (undergo reduction) to form the stable [Mn(CO)5]^- ion, making it act as an oxidizing agent. This corresponds to option (a).