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

A curved lined graph is shown. The y axis of the graph has the title Potential Energy. The x axis of the graph has the title Reaction Pathway. The graph curve begins at a lower level and ends at a slightly higher level. A vertical line labeled A, starting from the x axis till the beginning of the graph line is shown. A vertical line labeled B, starting from where the line labeled A ended, till the uppermost hump in the graph curve is shown. Another vertical line labeled C is shown from starting from the x axis till the point where the graph curve ends.

Part 1: Describe how you can determine the total change in enthalpy and activation energy from the diagram, and if each is positive or negative.

Part 2: Describe how the curve will look if the reaction was exothermic. Be sure to mention changes in the potential energies of the reactants and products and the sign changes of the enthalpy.