Answer: 0.
- A +2
- B 0
- C +4
- D +1
Correct answer: B. 0
Explanation: CO is a neutral ligand and the complex is neutral, so the oxidation state of Ni is 0. Metal carbonyls typically have the metal in a zero oxidation state.
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.