Question

In the coordination entity [Co(NH3)3(NO2)3], if all three N atoms of the amine ligands occupy adjacent positions at the corners of an octahedral face, the geometrical isomer formed is known as _______ isomer.

(a) cis

(b) trans

(c) fac

(d) mer

I had been asked this question by my school principal while I was bunking the class.

Asked question is from Isomerism in Coordination Compounds topic in division Coordination Compounds of Chemistry – Class 12

Answer 1

The correct choice is (c) fac

Explanation: Octahedral entities of the type [MA3B3] form two types of isomers based on whether the same ligand groups occupy adjacent positions on the octahedral face (fac) or positions around the meridian of the octahedron (mer).