Overall energy change
What Overall energy change means in Chemistry GCSE, as defined for AQA.
Definitions of Overall energy change
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Reference: AQA
Energy absorbed for bonds broken minus energy released for bonds made; a negative result means the reaction is exothermic overall and a positive result means it is endothermic.
The difference between the sum of the energy needed to break bonds in the reactants and the sum of the energy released when bonds in the products are formed.
For an exothermic reaction this is negative, because forming the bonds in the products releases more energy than breaking bonds in the reactants requires.
The balance of the two processes: total energy needed to break reactant bonds minus total energy released when product bonds form.
The difference between the reactant and product levels.
Topics that use Overall energy change
- Reaction profiles (AQA GCSE)
- The energy change of reactions (HT only) (AQA GCSE)
Related terms
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