Answer: Titanium (TiCl 4 ) with organoaluminium compound.
- A Titanium (TiCl<sub>4</sub>) with organoaluminium compound
- B Iron, paired with an organoaluminium co-catalyst instead
- C Cobalt, paired with an organoaluminium co-catalyst instead
- D Platinum, paired with an organoaluminium co-catalyst instead
Correct answer: A. Titanium (TiCl<sub>4</sub>) with organoaluminium compound
Explanation: Ziegler-Natta catalyst: TiCl<sub>4</sub> + Al(C<sub>2</sub>H<sub>5</sub>)<sub>3</sub> (triethylaluminium), used for stereospecific polymerisation of alkenes.
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.