Choose incorrect stability order : (a) [Cu(NH3)4]^2+ < [Cu(en)2]^2+ < [Cu(trien)]^2+ (b) [Fe(H2O)6]^ — Coordination Compounds Chemistry Question

💡 Solution & Explanation

Step 1: Check the stability factors: chelation increases stability (a); splitting energy increases stability down a group (c); higher oxidation states are more stable (d). Step 2: For (b), NO2^- is a much stronger field ligand than NH3 on the spectrochemical series, so [Fe(NO2)6]^3- is expected to be more stable than [Fe(NH3)6]^3+. Step 3: Therefore, the stability order given in (b) is incorrect, which makes it the correct option.