Which one of the following statements is correct for shape selective catalysts? a]The catalytic reaction does not depend upon the pore structure of the catalyst b]Zeolites are not shape selective catalysts because of their honeycomb like structure. c]Shape selective catalysts are microporous aluminosilicates with 3D network of silicate d]ZSM-5 is a shape selective catalyst which converts alcohol into acids.
Answers
Answer:
12th
Chemistry
Surface Chemistry
Catalysis
Which one of the following ...
CHEMISTRY
avatar
Asked on December 30, 2019 by
Monisha Krish
Which one of the following statements is not correct about zeolites?
MEDIUM
Share
Study later
ANSWER
The catalytic reaction that depends upon the pore structure of the catalyst and the size of the reactant and product molecules is called shape-selective catalysis. Zeolites are good shape-selective catalysts because of their honeycomb-like structures. An important zeolite catalyst used in the petroleum industry is ZSM-5. It converts alcohol directly into gasoline (petrol).
This is because of the following:
(A) Zeolites are natural ion exchangers. They take up calcium ions from hard water and release sodium ions in water. Hence, they act as water softeners. Hence, option A is correct.
(B) Zeolites trap small molecules (such as water, ammonia and carbon dioxide) in their interstices reversibly. Hence, they act as molecular sieves. Thus, option B is not correct.
(C) Zeolites are complex oxide catalysts commonly used in petrochemical industries. Hence, option C is correct.
(D) The activity of zeolites is increased by heating them in a vacuum. Hence, option D is correct