Can someone explain to me how to find the activation energy on a graph for an exothermic reaction?

Question

anonymous · Answer

Judging from a 10-second google image search of 'exother,ic reaction graph' it's the vertical distance between the peak point of the graph and the point where it crosses the y axis (or perhaps the leftmost point) as measured in the units of the y axis (kilojoules?).

anonymous · Answer

I know that is has something to do with the reactants and the maximum energy and you had to calculate something somewhere between that.

anonymous · Answer

It's the energy value at the peak of the graph minus the initial energy value of the reactants.