Draw a Potential Energy Curve for this Reaction (Given Mechanism) 

Yes. I think he meant to draw the third hump bigger than the second but smaller than the first.

@@luker.6967 No , the catch is the step with highest activation energy isn't the rate -determining step, Rather the step with the highest transition energy is the rate-determing step.

TwoEzy- VEGITO exactly

AJ Jaber most likely you’ll be given the equation and you use Hess law equation to figure out delta H If your delta H is a negative it is exothermic and if it is positive it is endothermic!

If they don't give you delta H, then you have to look at the diagram and where the reactants vs the products are, when its exothermic the reactants are at a higher point than the products,(b/c there was a release of energy) like in the video. When its endothermic the reactants are at the lower point and the products are at a higher point.(b/c energy was absorbed) this link has both graphs together, : www.khanacademy.org/test-prep/mcat/chemical-processes/thermochemistry/a/endothermic-vs-exothermic-reactions u gotta scroll down a bit tho.

my understanding is because the change in enthalpy is negative, (-100 kJ), this means the reaction is releasing energy, this energy is released in a variety of ways but mostly heat, so the reaction is thus exothermic

梵天丸 Damm he 12 years old doing university chem already?

@@xXMissAnimeLOVERXx Chinese

They are all on the reactant (left) side. "Cancelling" here means you need one of them to be on the reactant side and one of them to be on the product (right) side.