Read the passage carefully and answer the questions.
The transition metals and their compounds are known for their catalytic activity. This activity is ascribed to their ability to adopt multiple oxidation states and to form complexes. Vanadium(V) oxide (in Contact Process), finely divided iron, and nickel (in Catalytic Hydrogenation) are some of the examples. Catalysts at a solid surface involve the formation of bonds between reactant molecules and atoms of the surface of the catalyst (first row transition metals utilise 3d and 4s electrons for bonding). This has the effect of increasing the concentration of the reactants at the catalyst surface and also weakening of the bonds in the reacting molecules (the activation energy is lowering). Also because the transition metal ions can change their oxidation states, they become more effective as catalysts.
\( \text{TiCl}_4+\text{Al(CH}_3\text{)}_3 \) is used as catalyst in_______
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Ziegler-Natta catalysis
Many transition metals and their compounds are industrial catalysts, each for its own process. A mixture of titanium tetrachloride and a trialkylaluminium such as \( \ce{Al(CH3)3} \) is the Ziegler(–Natta) catalyst. It polymerises alkenes such as ethene at low pressure, and is used to make polyethylene (polythene):
\( \displaystyle n\,\ce{CH2=CH2} \xrightarrow{\ce{TiCl4 + Al(CH3)3}} \ce{(CH2-CH2)}_{n} \)
NCERT (2026-27 edition):
Some Applications of d- and f-Block Elements – “… Many of the metals and/or their compounds are essential catalysts in the chemical industry. V2O5 catalyses the oxidation of SO2 in the manufacture of sulphuric acid. TiCl4 with Al(CH3)3 forms the basis of the Ziegler catalysts used to manufacture polyethylene (polythene). Iron catalysts are used in the Haber process for the production of ammonia from N2/H2 mixtures. Nickel catalysts enable the hydrogenation of fats to proceed. In the Wacker process the oxidation of ethyne to ethanal is catalysed by PdCl2.”