The diagram shows the potential energy changes for a reaction pathway.

Part 1: Does the diagram illustrate an endothermic or an exothermic reaction? Give reasons in support of your answer.

Part 2: Describe how you can determine the total change in enthalpy and activation energy from the diagram and if each is positive or negative.

Part 1: it is a endothermic reaction because the potential energy level at the finishing point(point c) is higher than the potential energy level at the start of the reaction (point a).

Part II change in enthalpy/delta H = ending energy - beginning energy(if the result is positive, it is endothermic reaction. If it is negative, it is exothermic reaction). The highest point - starting energy = activation energy. Beginning potential energy - ending potential energy = change in enthalpy. It is all relative, not in absolute term when it comes to reactions.