Answer: I- 2 O 3 < en < CN- < CO.
- A I- < Br- < Cl- < F- < OH- < H<sub>2</sub>O < NH<sub>3</sub> < en < CN- < CO
- B CO < CN- < NH<sub>3</sub> < F- < Cl-, listed in the reverse field-strength order
- C All ligands shown to have identical field strength toward any metal
- D The field strength ranking depending entirely on which metal is used
Correct answer: A. I- < Br- < Cl- < F- < OH- < H<sub>2</sub>O < NH<sub>3</sub> < en < CN- < CO
Explanation: Weak field (halides, water) to strong field (NH<sub>3</sub>, en, CN-, CO). CO is the strongest due to extensive pi-backbonding.
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.