Q. Among the following complexes the one which shows zero crystal field stabilization energy (CFSE) is :
A) $[Mn(H_2O)_6]^{3+}$
B) $[Fe(H_2O)_6]^{3+}$
C) $[Co(H_2O)_6]^{2+}$
D) $[Co(H_2O)_6]^{3+}$
Explanation
[Solution] $Fe^{3+}$ is $d^5$; with weak-field water it is high spin $t_{2g}^3e_g^2$: CFSE = 3(−0.4) + 2(0.6) = 0. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.