Zeolites are used as catalyst in (a) Petrochemical industries during cracking (b) In the preparation of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (c) In the hydrolysis of ester (d) All

Catalytic cracking is a fundamental process within the petrochemical industry used to break down large, complex hydrocarbon molecules into smaller, more valuable products like gasoline, diesel and other alkanes. This is achieved by using a catalyst to lower the energy required for the reaction to proceed.

Zeolites, with their unique crystalline structure composed of silicon, aluminum, and oxygen, provide an excellent acidic surface that effectively catalyzes these cracking reactions. Their high surface area and pore structure allow them to facilitate the conversion of heavy hydrocarbons into lighter fractions more efficiently compared to other catalysts.

Catalysis is a crucial process in chemistry where the rate of a chemical reaction is increased by the addition of a substance known as a catalyst. This substance remains unchanged at the end of the reaction and can be used repeatedly.

In the context of zeolites, their role as catalysts is due to their ability to speed up reactions while remaining structurally intact. They function especially well in acid-catalyzed reactions, such as isomerization, alkylation, and of course, catalytic cracking. The catalyst offers an active site that provides an alternative reaction pathway with a lower activation energy, ensuring that more reactant molecules can transform into products over a given time.

Zeolites are a class of minerals known as microporous aluminosilicates, which means they have a porous structure made from interconnected aluminum, silicon, and oxygen atoms. This structure creates channels and cavities of precise sizes that can trap molecules fitting their pores, acting as molecular sieves.

The uniformity in the size of these pores allows zeolites to selectively absorb certain molecules while excluding others, which is beneficial in various applications such as adsorption, ion exchange, and as catalysts. These properties make zeolites invaluable in industries, where they contribute to processes such as water purification, gas separation, and the synthesis of fine chemicals.

Hydrolysis of esters is a chemical reaction where esters react with water to produce an alcohol and a carboxylic acid. This reaction typically requires an acidic or basic condition to proceed efficiently.

Zeolites provide the acidic sites necessary for catalyzing the hydrolysis of esters. Their capability to facilitate this transformation with high selectivity and under mild conditions is highly appreciated in both industrial applications and laboratory settings. The unique acidic properties of zeolites help in breaking the ester bonds, thereby increasing the reaction rate without the need for strong liquid acids, making the process environmentally friendlier and easier to control.