Science, Tech, Math › Science Examples of Endothermic Reactions Share Flipboard Email Print ThoughtCo / Hilary Allison Science Chemistry Physical Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated April 09, 2020 Here's a list of examples of endothermic reactions. You can use these when asked to cite an example or to get ideas to set up a demonstration of an endothermic reaction or process. Endothermic Reaction Definition An endothermic reaction is any chemical reaction that absorbs heat from its environment. The absorbed energy provides the activation energy for the reaction to occur. A hallmark of this type of reaction is that it feels cold. Endothermic Chemical Reactions A good example of an endothermic reaction includes dissolving a salt. It doesn't have to be table salt, nor does the solvent need to be water. The reaction of barium hydroxide octahydrate crystals with dry ammonium chlorideDissolving ammonium chloride in waterThe reaction of thionyl chloride (SOCl2) with cobalt(II) sulfate heptahydrateMixing water and ammonium nitrateMixing water with potassium chlorideReacting ethanoic acid with sodium carbonatePhotosynthesis (chlorophyll is used to react to carbon dioxide plus water plus energy to make glucose and oxygen) Endothermic Processes These examples could be written as chemical reactions, but are more generally considered to be endothermic or heat-absorbing processes: Melting ice cubesMelting solid saltsEvaporating liquid waterConverting frost to water vapor (melting, boiling, and evaporation, in general, are endothermic processesMaking an anhydrous salt from a hydrateForming a cation from an atom in the gas phaseSplitting a gas moleculeSeparating ion pairsCooking an eggBaking bread Endothermic and Endergonic An endothermic reaction is a type of endergonic reaction. However, not all endergonic reactions are endothermic. Endothermic reactions involve heat absorption. Other forms of energy that might be absorbed in an endergonic reaction include sound and light.