Question

The co-ordination number of Cr in \( [Cr(C_2O_4)_3]^{3-} \) ion is:

• A. 0
• B. 1
• C. 2
• D. 3

Hint:

Co-ordination number is the total number of coordinate bonds formed between the central metal and ligands.

Answer 1

The Correct Option is D

The \( C_2O_4^{2-} \) (oxalate) ligand is bidentate, meaning it donates two pairs of electrons to the central metal atom. Since there are three oxalate ligands, the co-ordination number of Cr is: \[ 3 \times 2 = 6. \]