alleryWhich of the following ions is NOT coloured in aqueous solution?
ACu²⁺
BSc³⁺ (3d⁰, no d-electron, no d-d transition)
CFe³⁺
DMn²⁺
Answer & Solution
Correct answer: B. Sc³⁺ (3d⁰, no d-electron, no d-d transition)
**Sc³⁺ (3d⁰) is colourless** — no d electron, hence no d-d transition possible.
Same for Ti⁴⁺ (d⁰), Zn²⁺ (d¹⁰), Cu⁺ (d¹⁰).
All other 3d^n (1≤n≤9) ions exhibit colour.
Keep practising d- and f-Block Elements
Browse all d- and f-Block Elements questions for AP Intermediate 2nd Year, or explore more Chemistry topics.
Related questions
Why is Sc³⁺ colorless?Eu²⁺ is more stable than other Ln²⁺ because:Number of unpaired electrons in [Mn(CN)₆]³⁻ (Mn(III), d⁴, strong field CN⁻):Magnetic moment of [Fe(H₂O)₆]³⁺ (Fe³⁺ is d⁵, weak field H₂O → high spin):Coordination number of Ag in [Ag(CN)₂]⁻:K₂Cr₂O₇ (potassium dichromate) is a strong:Magnetic moment of complex with 5 unpaired d-electrons (high spin):Which transition metal forms unstable highest oxidation state +7?