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Endothermic reaction

Energy flowChemical reaction that absorbs energy from

surrounding

Energy content in the reaction Lower than the energy content in the reacting

substances

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Energy level in diagrammatic form

Examples

Dissolving ammonium chloride in waterDecomposition of copper (II) carbonate when

heated

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Exothermic reaction

Energy flowChemical reaction that produces energy into

surrounding

Energy content in the reactionHigher than the energy content in the reacting

substances

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Energy level in diagrammatic form

Examples

Freezing of water into ice Boiling of water into air

Dissolving Sodium Chloride Crystals in water