Question

Point out incorrect stability order

• A. \( [Cu(NH_3)_4]^{2+}<[Cu(en)_2]^{2+}<[Cu(trien)]^{2+} \)
• B. \( [Fe(H_2O)_6]^{3+}<[Fe(NO_2)_6]^{3+}<[Fe(NH_3)_6]^{3+} \)
• C. \( [Co(H_2O)_6]^{3+}<[Rh(H_2O)_6]^{3+}<[Ir(H_2O)_6]^{3+} \)
• D. \( [Cr(NH_3)_6]^{3+}<[Cr(NH_3)_6]^{2+}<[Cr(NH_3)_6]^{3+} \)

Hint:

The stability of complex ions depends on the charge and the ligand environment. Higher oxidation states tend to form more stable complexes with certain ligands.

Answer 1

The Correct Option is D

The incorrect stability order is option (4) because it shows the same complex ion, \( [Cr(NH_3)_6]^{3+} \), appearing twice with contradictory charge states.