GCSE›AQA GCSE Chemistry›Mind mapsExothermic and Endothermic ReactionsAQA GCSE Chemistry: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsExothermicEnergy transferred to surroundingsTemperature of surroundings risesΔH is negativeCombustion, neutralisation, rustingEndothermicEnergy taken in from surroundingsTemperature of surroundings fallsΔH is positiveThermal decomposition, citric acid + sodium hydrogencarbonateEnergy profilesExothermic: products lower than reactantsEndothermic: products higher than reactantsHump up to a peak shows activation energyΔH = products − reactantsEnergy Changesexo and endothermicΔHEakJActivation energyMinimum energy for particles to react on collisionAlways positive, even if exothermicCatalysts lower itMatch or spark starts natural gas burningEveryday usesHand warmers and self-heating cansCold packs for sports injuriesExam tipsSay energy transferred to surroundings, not just releasedDo not confuse Ea with ΔHExothermic still needs activation energy