Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: Exothermic and exergonic reactions releases energy from the system

Learn more physics!

Most recent answer: 04/11/2012
Q:
Greetings, Is there a term or word to describe regarding energy output "an action which produces more energy than is used to prepare"
- philip urkov (age 35)
huntington beach ca usa
A:
Hello Philip,

I think the term you are looking for is either "exothermic" or "exergonic".
An exothermic reaction is one whereby energy is released from the system into the environment usually in the form of heat or light. The converse is an endothermic reaction. Both of these reactions relate to the enthalpy change of the process.
An exergonic reaction is one whereby energy is also released from the system into the environment. The converse is an endergonic reaction. Both these reactions relate to the Gibbs free energy change in the reaction.

I would like to point out that if "an action produces more energy than is used to prepare", the additional energy that is produced would have to come from somewhere else--usually it is from the chemical bonds within the molecules. In other words the energy was already there in some form or other.

Maurice

(published on 04/11/2012)

Follow-up on this answer.