ZSM-5 is a catalyst used for:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Converting alcohols into gasoline
ZSM-5 is a zeolite, a shape-selective catalyst used in the petroleum industry. It converts alcohols directly into gasoline (petrol) by dehydrating them to give a mixture of hydrocarbons. Its pore size allows only molecules of a particular size and shape to react.
Why the other options are incorrect
Option (1) Converting zinc into aluminium — Incorrect. A catalyst cannot change one element into another; that would need a nuclear reaction.
Option (3) Converting zeolites into zinc — Incorrect. Zeolites are aluminosilicates and contain no zinc; ZSM-5 is itself a zeolite, the catalyst, not a reactant.
Option (4) Converting zinc to zeolites — Incorrect. Zeolites are not made from zinc; ZSM-5 does not act on metals at all.
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Shape-selective Catalysis by Zeolites – “… Zeolites are being very widely used as catalysts in petrochemical industries for cracking of hydrocarbons and isomerisation. An important zeolite catalyst used in the petroleum industry is ZSM-5. It converts alcohols directly into gasoline (petrol) by dehydrating them to give a mixture of hydrocarbons.”