Answer: Cisplatin [cis-Pt(NH 3 ) 2 Cl 2 ].
- A Cisplatin [cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>]
- B K2[PtCl<sub>4</sub>] as frequently described
- C [Co(NH<sub>3</sub>)<sub>6</sub>]Cl3 in most textbook accounts
- D [Fe(CN)<sub>6</sub>]4- during normal conditions
Correct answer: A. Cisplatin [cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>]
Explanation: Cisplatin (cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>) is the most widely used platinum-based anticancer drug; it cross-links DNA strands, preventing cell division.
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.