Activation Energy

[Sarah Sharma 2J]

When activation energy is at its optimum, what does that mean for collisions? Are they taking place at the fastest at this point?

[Zane Mills 1E]

Not really sure what you mean by optimum but activation energy is essentially an energy barrier between reactants and products. It's not so much collisions as it is stability, as catalysts help to stabilize intermediates and bring down the 'barrier' between products and intermediates. I guess optimum would be a good word for the enzyme b/c the better the enzyme the lower the Ea and thus the faster the rxn will proceed.

[Nathan Tu 2C]

If activation energy is reached in the reactants, then when the reactants collide to form a product or intermediate, they will form the product/intermediate. Without reaching the activation energy required, reactant collisions will temporarily create the product but then reverse back into reactants because of insufficient energy.

[Varsha Sivaganesh 1A]

I wouldn't necessarily describe this situation as having an "optimum" activation energy. Think of it as, if there is enough energy supplied, then the reactants can reach the activation energy which means they have enough energy to break bonds so that the reaction can occur. If activation energy is lowered (i.e. through use of a catalyst), then the reaction can occur faster.

[Guangyu Li 2J]

If the kinetic energy of the molecules reaches the activation energy, they will be able to collide with each other effectively and allow the reactions to proceed.

The reactions can be speeded up by lowering the energy barrier of the reactions. One of the most significant examples of this point is the catalyst. If the activation energy required for a reaction decreases, it will proceed faster than before.