Question

The co-ordination number of Fe and Co in the complex ions, [F_e(C₂O₄)3]^3- and [Co(SCN)₄]^2- are respectively

• A. 6 and 4
• B. 3 and 4
• C. 6 and 8
• D. 4 and 6

Answer 1

The Correct Option is A

1. For the complex ion [Fe(C\(_2\)O\(_4\))\(_3\)]\(^3-\):
The oxalate ion (C\(_2\)O\(_4\)) is a bidentate ligand, meaning it forms two bonds with the central metal ion.
Since there are 3 oxalate ions in the complex, each forming two bonds with Fe, the total coordination number of Fe is \( 3 \times 2 = 6 \).
2. For the complex ion [Co(SCN)\(_4\)]\(^2-\):
The thiocyanate ion (SCN\(^-\)) is a monodentate ligand, meaning it forms only one bond with the central metal ion.
Since there are 4 SCN\(^-\) ions in the complex, the coordination number of Co is 4.
Thus, the coordination numbers are: Fe: 6, Co: 4

The correct option is (A): 6 and 4