Answer: Cisplatin [cis-Pt(NH3)2Cl2].
- A Cisplatin [cis-Pt(NH3)2Cl2]
- B K2[PtCl4] as frequently described
- C [Co(NH3)6]Cl3 in most textbook accounts
- D [Fe(CN)6]4- during normal conditions
Correct answer: A. Cisplatin [cis-Pt(NH3)2Cl2]
Explanation: Cisplatin (cis-Pt(NH3)2Cl2) 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.