The Energy Change of Reactions (OCR GCSE Chemistry A, Combined (Gateway Science Suite)): Flashcards

Energy cannot be created or destroyed, only transferred

The chemical reaction being studied

Everything outside the reaction (container, environment)

Reaction that releases energy to the surroundings

Temperature goes up

Reactants have more energy than products

Reaction that absorbs energy from the surroundings

Temperature goes down

Products have more energy than reactants

Energy must be absorbed from surroundings

Energy is released to the surroundings

$\text{Energy Change} = \text{Sum of Bonds Broken} - \text{Sum of Bonds Made}$

Exothermic reaction (energy released overall)

Endothermic reaction (energy absorbed overall)