What is a heterogeneous catalytic reaction?

A heterogeneous catalytic reaction is a type of catalytic reaction in which the catalyst and the reactants are in different phases. The catalyst is usually in a solid state, while the reactants are in either a liquid or gaseous state. The reactants come into contact with the catalyst surface, where the reaction takes place.

Explanation of the options:

a) Ostwalds process: The Ostwald process is a well-known heterogeneous catalytic reaction used for the production of nitric acid. In this process, ammonia is oxidized to nitric oxide using a platinum-rhodium catalyst.

b) Habers process: The Haber process is another example of a heterogeneous catalytic reaction. It is used for the production of ammonia from nitrogen and hydrogen gases. The reaction takes place over an iron catalyst.

c) Combustion of coal: The combustion of coal is not an example of a heterogeneous catalytic reaction. It is a combustion reaction, where coal (a solid) reacts with oxygen (a gas) to produce carbon dioxide, water, and heat. No catalyst is involved in this reaction.

d) Hydrogenation of vegetable oils: The hydrogenation of vegetable oils is a common example of a heterogeneous catalytic reaction. It involves the addition of hydrogen gas to unsaturated fatty acids, such as those found in vegetable oils, to produce saturated fatty acids. The reaction takes place over a metal catalyst, typically nickel or palladium.

Conclusion:

Based on the explanations provided, option c) "Combustion of coal" is not an example of a heterogeneous catalytic reaction. In this reaction, no catalyst is involved, and it is a simple combustion process. Options a), b), and d) are all examples of heterogeneous catalytic reactions, where a solid catalyst facilitates the reaction between different phases of reactants.

It does not require a catalyst for combustion of coal ..