ABSTRACT
In a chemical reaction, reactants decrease in quantity while the quantity of products increases. Chemical kinetics deals with this aspect of chemical reactions. Chemical reactions involve breaking of existing bonds and formation of new bonds. The time scale on which the breaking and making of bonds take place decides the time required for the accomplishment of a chemical reaction. Elementary reactions are exceptions rather than the rule. For the vast majority of reactions, the transformation of reactants into products is “not a single event– at the molecular level. Certain reactions undergo an appreciable change in the reaction rate upon the addition of a substance other than the reactants. Owing to their overwhelming commercial importance, the fluid-solid catalytic reactions have drawn much attention. Solid catalysts enable us to carry out chemical transformations of gaseous or liquid reactants that are otherwise unviable. In relation to catalyst deactivation, coke refers to carbonaceous substances that are formed during solid-catalyzed reactions.
