Energy in a Chemical Reaction
your question is good yet lacks the specifics. 
there are different so called "energy fields" in which changes occur (entropy, potential ,gibes and so forth).
the thermodynamic field is endless and can be spanned with any variables (using maxwells equations and Legendre transformation) 
there is 
a sort of an axiom that states that all matter will try to find a way to a lower state of energy. 
but that said its not to scientific. 

now for the question:
every reaction creates some amounts of electromagnetic waves (as a price for electron "movement") some can be seen with the naked eye as they emit waves in the Uv-vis spectrum some are just infrared radiations of inner states of electron decay to a lower energetic state via vibrational relaxation. 

ideally no reaction will occur in the ideal zero as there is no energy to "pay" for any kind of a reaction.

for further read:
quantitive chemical analysis by harris 
chapter 17 fundamentals of spectrophotometry.