GCSE›Edexcel GCSE Chemistry›Mind mapsHeat Energy Changes in Chemical ReactionsEdexcel GCSE Chemistry: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsWhere it happensSalts dissolving in waterNeutralisation reactionsDisplacement reactionsPrecipitation reactionsMeasure the temperature changeExothermicHeat given out to surroundingsSurroundings warm upCombustion and neutralisationEndothermicHeat taken in from surroundingsSurroundings cool downDissolving ammonium nitrateEnergy changesheat in reactionskJ°CBondsBreaking bonds is endothermicMaking bonds is exothermicMore energy released → overall exothermicEnergy change = broken − madeNegative result = exothermicReaction profilesActivation energy: minimum energy to reactExothermic: products lower than reactantsEndothermic: products higher than reactantsMeasure it from the reactants to the peakExam tipsCompare energy released with energy neededActivation energy is not the full hump height