Answer: Oxalate ion.
- A Chloride ion
- B Ammonia
- C Water
- D Oxalate ion
Correct answer: D. Oxalate ion
Explanation: Oxalate (C<sub>2</sub>O<sub>4</sub><sup>2-</sup>) is bidentate and forms a ring (chelate) with the metal. Cl<sup>-</sup>, NH<sub>3</sub> and H<sub>2</sub>O are monodentate.
The three common coordination geometries: octahedral (6 ligands), tetrahedral (4 ligands), and square planar (4 ligands in one plane).
Concept context
Study of compounds where a central metal atom is bonded to surrounding ligands. Covers nomenclature, types of isomerism, bonding theories (VBT, CFT), and applications in medicine, photography, and industry.