Question

Which of the following is/are inner orbital complexes as well as paramagnetic with magnetic moment equal to 3.78 (approximate)?

• A. [Co(ox)3]3–
• B. [Cr(NH3)6]3+
• C. [Fe(H2O)5NO]2
• D. [Zn(NH3)6]2+

Answer 1

Answer: (B)

$Cr(NH3)6$3+

Answer 2

(1) [Co(ox)3]3– ; 3d6 configuration, all electrons are paired and hybridisation is d2sp3–diamagnetic with m = 0.

(2) [Cr(NH3)6]3+ ; 3d3 configuration, all electrons are unpaired and paramagnetic with m (approximately)3.78 B.M and hybridisaion is d2sp3 (NH3 strong field ligand).

(3) [Fe(H2O)5NO]2+ ; 3d6 4s1 configuration, hybridisation is sp3d2 and is paramagnetic with three unpaired electrons (m » 3.78 B.M.)

(4) [Zn(NH3)6]2+ ; 3d10 configuration, all electrons are paired so diamagnetic with m = 0 and hybridisation is sp3d2.