Answer:
175KJ
Explanation:
I will assume the diagram is as in the attachment I’ve supplied herein.
Activation energy is the minimum energy required by reactant particles for a chemical reaction to occur. Depending on reaction conditions, especially for reversible reactions, reactants can become products and vice versa.
Activation energy for a forward reaction = energy of the activated complex (transition state) – energy of the reactants.
Activation energy for a reverse reaction = energy of the activated complex – energy of the products.
For the forward reaction above, reading the values from the diagram,
Activation energy = energy of the activated complex –energy of the reactants
Activation energy = (400 – 225)KJ = 175KJ