Consider a reaction that occurs by the following mechanism:

A + BC → AC + B

AC + D → A + CD

The potential energy profile for this reaction is as follows:

(d) Is the reaction endothermic or exothermic? Add labels to the diagram that show the values of the energy of reaction ΔE and the activation energy Ea for the overall reaction.

Video transcript

Hello everyone today. We have the following question. A certain reaction involves the following two step reaction mechanism. The energy diagram for the reaction is given below determine whether reaction, whether the reaction is endo thermic or XR. Thermic provide the labels, any diagram that represents the energy of the reaction and the overall reaction's activation energy. So the first thing you want to account for is that the energy of the reaction is equal to the energy of our products minus the energy of our reactant. If the energy of our reactant is greater than the energy of our products, this is said to have a negative overall change in energy as well as be indicative of an exhaust thermic reaction. So if we look at our graph here, our energy diagram i is going to represent our reactant or one is going to represent our reactant and our products are going to be represented by five. And we see here that the energy of our reactant is in fact greater than that of our products. And so we can say this is an ex ah thermic reaction. So we can say that this reaction is exo thermic. And so that's one part of this question. To note the energy difference or the energy of the reaction to label it on the energy diagram, we're simply gonna go from where the energy of our reactant ends and where the energy of our products begins and that's going to be this space labeled as such. And this is going to be the energy of the reaction. Now the activation energy or east of A is going to essentially be from a point where we have the higher transition state minus the energy of our reactant. For example, if we will go to the highest peak, that's going to be at Roman numeral four here and we already labeled the energy of the reactant. And so this space that is being labeled as such is going to be our activation energy for the reaction. And so with that we have answered the question overall, I hope this helped. And until next time.