Question

Let's say I have two different reactions, each with their own unique rectant. In both rections, the concentration and recation contants are equal. The only differnce between the two reactions is the tempature of the system as in the first system the tempature is lower than that of the second. Can you determine from this infomation which reaction will have a larger activation energy barrier?

Answer 1

Activation energy barrier is the barrier that is present between reactants and products , which is determined by the change in product's and reactant's energy.

Now if the reactants are different for 2 reactions , their activation energy barrier cannot be compared as both of the reactants will have different energies to start from .

Secondly, the energy barrier does not have any relation with the temperature . Though you may see an increase in the rate of reaction ,as the temperature increases , it is not due to the lowering of activation energy barrier but it is due to the fact that reactants gain kinetic energy on higher temperature , due to which they collide more frequently , and more number of it can cross the barrier and convert into products .

So though the temperature is kept constant for these 2 reactions , the energy barrier cannot be determined .