When the transformation occurs at constant pressure:
and constant volume:
In an adiabatic system (e.g. a system that does not give off heat to the surroundings), an exothermic process results in an increase in temperature.
In chemical reactions, the heat that is released is in the form of electromagnetic energy. The loss of kinetic energy via reacting electrons causes light to be released. This light is equivalent in energy to the stabilization energy of the energy for the chemical reaction, i.e. the bond energy. This light that is released can be absorbed by other molecules in solution to give rise to molecular vibrations or rotations, which gives rise to the classical understanding of heat. In contrast, when endothermic reactions occur, energy is absorbed to place an electron in a higher energy state, such that the electron can associate with another atom to form another chemical complex. The loss of energy within solution is absorbed by the endothermic reaction and therefore is a loss of heat. This is the physical understanding of exothermic and endothermic reactions within solution.
Some examples of exothermic processes are:
Insulating or exothermic? Steel casters state their cases: metalcasters share their practices and preferences for insulating and exothermic riser sleeves in a recent survey.
May 01, 2011; Steel casters have developed their own rules for using insulating or Exothermic riser sleeves based on observation or...
WIPO ASSIGNS PATENT TO MYCOAL FOR "EXOTHERMIC BODY AND METHOD FOR MANUFACTURING EXOTHERMIC BODY" (JAPANESE INVENTORS)
Mar 14, 2011; GENEVA, March 14 -- Publication No. WO/2011/027495 was published on March 10. Title of the invention: "Exothermic BODY AND...
WIPO ASSIGNS PATENT TO YOU&I TECH FOR "EXOTHERMIC ENAMEL GLAZE, AND EXOTHERMIC CONTAINER COATED WITH SAME" (SOUTH KOREAN INVENTORS)
Oct 14, 2010; GENEVA, Oct. 18 -- Publication No. WO/2010/117137 was published on Oct. 14. Title of the invention: "Exothermic ENAMEL...