Endothermic vs. Exothermic Reactions: By: Crystal & Caitlin! :D

Endothermic: Endothermic Reaction: a reaction in which the products have more stored energy than the reactants. The reaction absorbs energy from the surrounding environment and the products use up this energy to create chemical bonds. The products are colder than the reactants.

An Exothermic reaction is the combustion of Acetone peroxide.

The Definitions Exothermic- the word describes a process that releases energy in the form of heat. Forming a chemical bond releases energy and therefore is an exothermic process. Exothermic reactions usually feel hot because it is giving heat to you. Endothermic - a process or reaction that absorbs energy in the form of heat. Breaking a chemical bond requires energy and therefore is Endothermic. Endothermic reactions usually feel cold because it is taking heat away from you.

The endothermic process. Freezing water Solidifying solid salts Condensing water vapor Making a hydrate from an anhydrous salt Forming an anion from an atom in the gas phase Annihilation of matter E=mc2 Splitting of an atom

The exothermic processes Melting ice cubes Melting solid salts Evaporating liquid water Making an anhydrous salt from a hydrate Forming a caution from an atom in the gas phase Splitting a gas molecule Separating ion pairs Cooking an egg Baking bread

Exothermic change

Endothermic change

Interesting Process: * Endothermic = Melting ice. In order for ice to melt, it needs to draw in the heat (energy) from its surroundings. The ice becomes less stable as it responds to the increased heat. The ice's stored energy decreases. The end product is water, which has a higher energy level than the ice.

Interesting Process: * Exothermic = Lighting a match. When the head of the match is struck, it results in the spontaneous release of stored energy (heat) from the reactants into the surroundings. The flame that is produced has a lower level of energy than the match and the striking surface because the reaction is giving off stored energy and not required to draw energy in from its surroundings.

Some examples:

Glow sticks are examples of a Exothermic reaction

What does this mean? Exothermic reactions release energy, where endothermic reactions absorb energy. Hand warmers, glow sticks and self heating coffee - all applications of exothermic and endothermic reactions.

Citations: . "Endothermic Versus Exothermic Reactions." . N.p.. Web. 15 Nov 2012. <http://www.emsb.qc.ca/laurenhill/science/exo.html\ Holbrook, Terry. "What are some examples of exothermic and endothermic processes? ." General Chemistry Online!. Fred Senese, 15 2010. Web. 15 Nov 2012. <http://antoine.frostburg.edu/chem/senese/101/thermo/fa/exothermic-endothermic-examples.shtml>.