Combustion reactions can only be exothermic. In chemical reactions, old bonds are broken to form new ones. Depending on the energy difference between broken and formed bonds, the total reaction energy is either positive ... More »

Evaporation is an endothermic process. These types of reactions occur when the temperature of the system decreases and the surroundings gain energy. Endothermic reactions end up with an overall positive heat of reaction. More »

Vaporization is an example of an endothermic reaction. In chemistry, vaporization is defined as the transformation of a solid or liquid into gas. This is caused by either evaporation or boiling. More »

Combustion reactions have a variety of uses including the burning of fuel that provides heat for the home or power for an automobile. Combustion of natural gas or propane gives the heat to cook one's food. Combustion of ... More »

Freezing water is an exothermic process because there is a release of energy into the environment in the form of heat. In an exothermic reaction, the change in enthalpy or measure of heat content, is negative. More »

Examples of exothermic processes include burning of coal, rust formation and dissolution of quick lime in water. On the other hand, some endothermic processes include dissolution of Ammonium Chloride in water and nitric ... More »

During endothermic reactions, energy is absorbed from the surrounding environment. The energy is typically transferred in the form of heat energy, and causes the reaction mixture and its environs to cool. A thermometer c... More »