中四Chemistry

Exothermic reactions release energy in the form of heat, light, or sound. One example of an exothermic reaction is the mixture of sodium andchlorine to yield table salt. This reaction produces 411 kJ of energyfor each mole of salt that is produced.

An endothermic reaction is any chemical reaction that absorbs heat from its environment. Procedures such as dissolving ammonium chloride in water or mixing water and ammonium nitrate will chill the apparatus. You can speed up the reactions by supplying heat.