Answer: dsp 2.
- A sp<sup>3</sup>
- B sp<sup>3</sup>d
- C dsp<sup>2</sup>
- D d<sup>2</sup>sp<sup>3</sup>
Correct answer: C. dsp<sup>2</sup>
Explanation: Ni<sup>2+</sup> (d<sup>8</sup>) with strong-field CN<sup>-</sup> pairs its electrons, freeing a 3d orbital; dsp<sup>2</sup> hybridisation gives a diamagnetic square planar complex.
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.