Answer: [Mn(H2O)6]2+.
- A [Co(NH3)6]3+
- B [Fe(CN)6]4-
- C [Mn(H2O)6]2+
- D [Ni(CN)4]2-
Correct answer: C. [Mn(H2O)6]2+
Explanation: Mn2+ is d5; with weak-field H2O it is high spin with 5 unpaired electrons, so mu = sqrt(5x7) = 5.92 BM. The others are low spin or diamagnetic.
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.