Zaymiey

🧪 Chemistry  ·  d- and f-Block Elements  ·  NEET & JEE

The crystal field stabilisation energy (CFSE) for d3 in an octahedral field is:

Answer: -1.2 Delta_o (three electrons each in t2g, each contributing -0.4 Delta_o).

  • A -1.2 Delta_o (three electrons each in t2g, each contributing -0.4 Delta_o)
  • B Zero, since a d3 configuration shows no net stabilisation in routine practice
  • C +1.2 Delta_o, a positive destabilisation for this configuration overall
  • D -0.8 Delta_o, corresponding instead to a d2 configuration in most cases

Correct answer: A. -1.2 Delta_o (three electrons each in t2g, each contributing -0.4 Delta_o)

Explanation: In an octahedral field, t2g electrons each lower energy by 0.4 Δo; for d3 (all in t2g): CFSE = 3 × (-0.4)Δo = -1.2Δo.

Colours of Common Transition Metal Ions (Aqueous)Cu²⁺ blueFe²⁺ pale greenFe³⁺ brown-yellowMn²⁺ pale pinkNi²⁺/Cr³⁺ greenColour arises from d-d electron transitions - d⁰ ions like Sc³⁺, Ti⁴⁺ are colourless

Aqueous solutions of transition metal ions show characteristic colours caused by electrons absorbing visible light to jump between split d-orbitals; the exact colour depends on the metal, its oxidation state, and surrounding ligands.

Concept context

Transition metals (d-block) and lanthanides/actinides (f-block). Known for coloured compounds, variable oxidation states, complex formation, and catalytic properties. Frequently tested in JEE and NEET.

Read the full d- and f-Block Elements notes →