Question

Some ions of transition metals are given below. Categorize them into those which are coloured or not. Justify your answer.

Ti³⁺,V²⁺, Sc³⁺, Mn²⁺, Ti⁴⁺, Cu²⁺, Zn²⁺,Cu⁺

Answer 1

Coloured ions	Colourless ions
Ti3+	Sc3+
V2+	Ti4+
Mn2+	Zn2+
Ca2+	Cu+

• In Ti³⁺, V²⁺, Mn²⁺, Ca²⁺d-d transition is possible. Hence they have colour.
• In Sc³⁺ and Ti⁴⁺ (3d⁰), Zn²+ and Cu+(3d¹⁰) d-d transition is not possible.