Answer: Purple/violet.
- A Purple/violet
- B Yellow
- C Green
- D Colourless
Correct answer: A. Purple/violet
Explanation: KMnO4 is deep purple due to charge-transfer in the MnO4- ion.
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.