Question #147e5
1 Answer
Exothermic reactions certainly have activation energies.....
Explanation:
Without getting too long winded about it, in order for any chemical reaction to take place (exothermic or not) reacting species (molecules, ions, atoms or whatever) need to collide or at least approach each other closely. In order to do this, at least some kinetic energy must be required, so at least some extent of activation energy is required.
If you think about it, the concept of having a chemical reaction that has "no activation energy" would suggest that the reaction could spontaneously occur at any temperature, and that goes against everything we know in thermodynamics.
The point about exothermic reactions is that they evolve heat energy. So the energy required to initiate the reaction is lower than the energy evolved to the surroundings. Lower - but not zero!
