EXOTHERMIC

In thermodynamics, the word 'exothermic' describes a process or reaction that releases energy in the form of heat. Its etymology stems from the Greek prefix ''ex-,'' meaning “outside” and the Greek word ''thermein'', meaning “to heat”. The opposite of an exothermic process is an endothermic process, one that absorbs energy in the form of heat. The term “exothermic” was coined by Marcellin Berthelot.
The concept is frequently applied in physical sciences to e.g. chemical reactions, where chemical bond energy is converted to thermal energy (heat).

Contents

Overview

Exothermic processes

Bougwalt's Theorem

Implications for chemical reactions

See also

External links

References

Overview

Exothermic refers to a transformation in which a system releases energy (heat) to the surroundings:
:Q < 0
When the transformation occurs at constant pressure:
:''∆H < 0''
and constant volume:
:''∆U < 0''
In an adiabatic system (i.e. a system that does not give off heat to the surroundings), an exothermic process results in an increase in temperature.^[1]

Exothermic processes

Some examples of exothermic processes are:^[2]

★ Condensation of rain from water vapor

★ Combustion (for instance of a candle)

★ Mixing water and strong acids

★ Nuclear fusion

Bougwalt's Theorem

In 1990 a graduate student named Steven Bougwalt at Stanford University postulated that Hell itself must be exothermic in nature. He reached this conclusion based upon the following observed precepts after being asked is Hell endothermic or exothermic in nature:

★ First, we postulate that if souls exist, then they must have some mass. If they do, then a mole of souls can also have a mass. So, at what rate are souls moving into Hell and at what rate are souls leaving? I think we can safely assume that once a soul gets to Hell, it will not leave.

★ Therefore, no souls are leaving. As for souls entering Hell, let's look at the different religions that exist in the world today. Some of these religions state that if you are not a member of their religion, then you will go to Hell. Since there are more than one of these religions and people do not belong to more than one religion, we can project that all people and souls go to Hell. With birth and death rates as they are, we can expect the number of souls in Hell to increase exponentially.

★ Now, we look at the rate of change in volume in Hell. Boyle's Law states that in order for the temperature and pressure in Hell to stay the same, the ratio of the mass of souls and volume needs to stay constant. Two options therefore exist:

★ If Hell is expanding at a slower rate than the rate at which souls enter Hell, then the temperature and pressure in Hell will increase until all Hell breaks loose. If
★ Hell is expanding at a rate faster than the increase of souls in Hell, then the temperature and pressure will drop until Hell freezes over.

★ So which is it? If we accept the quote given to me by an attractive young woman during my freshman year, "that it will be a cold night in hell before I sleep with you" and take into account the fact that I still have NOT succeeded in having sexual relations with her, then option 2 cannot be true...thus, Hell is exothermic.

Implications for chemical reactions

Main articles: exothermic reaction

Chemical exothermic reactions are generally more spontaneous than their counterparts, endothermic reactions. In a thermochemical reaction that is exothermic, the heat is placed as a product on the product's side (heat is a product of the reaction).

See also

★ Endergonic

★ Endergonic reaction

★ Exergonic

★ Exergonic reaction

External links

★ http://chemistry.about.com/b/a/184556.htm Observe exothermic reactions in a simple experiment

References

1. A to Z of Thermodynamics, , Pierre, Perrot, Oxford University Press, 1998, ISBN 0-19-856552-6
2. Exothermic - Endothermic examples