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Explain with the help of potential energy barrier how does a catalyst increase the speed of a reaction ? |
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Answer» Solution :(1) A catalyst is a substance, when added to the reactants, increases the rate of the reaction without veing consumed. (2) The catalyst provides alternaative and lower energy PATH or mechanism for the reaction. (3) In the presence of the catalyst, the activation energy of the reaction is lowered. The HEIGHT of activation energy barrier is less than that in the uncatalysed reaction. (4) Due to lowering of energy of activaion, `(E_(a))` the number of molecules possessing `E_(a)` increases, hence the rate of the reaction increases. (5) The rate CONSTANT `=k=Axxe^(-E_(a)//RT)` where A is a frequency factor and hence the rates of the catalysed reaction are higher than those of uncatalysed reactions. (6) The catalyst does not change the extent of the reaction but hastens the reaction. 
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