Why is Sc³⁺ colorless?
ARandom
BLight
CRandom
DSc³⁺ is 3d⁰ — no d electron for d-d transition
Answer & Solution
Correct answer: D. Sc³⁺ is 3d⁰ — no d electron for d-d transition
Sc³⁺: [Ar] 3d⁰. No d electron. No d-d transition. Hence colorless. Same logic: Ti⁴⁺ (3d⁰), V⁵⁺, Cr⁶⁺ would be colorless from d-d perspective (intense color in CrO₄²⁻ comes from LMCT).
Related questions
Magnetic susceptibility of Fe³⁺ vs Fe²⁺ in high-spin complexes: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):Oxidation state of Cu in [Cu(NH₃)₄]²⁺: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):