What does a bond energy indicate?
The energy needed to break a particular bond.
AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Higher · 5.5.1.3
Revise AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Higher specification point 5.5.1.3, The energy change of reactions (HT only), with free active-recall flashcards. Flip through the set or review every question and answer below.
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What does a bond energy indicate?
The energy needed to break a particular bond.
How is the overall energy change of a reaction calculated from bond energies?
Add the energies needed to break all reactant bonds, then subtract the total energy released when the product bonds form.
How does the balance between bond-breaking and bond-forming energies determine whether a reaction is exothermic or endothermic?
How are atoms rearranged during a chemical reaction?
Some existing bonds break, and new bonds form.
Why does breaking a chemical bond require energy?
Energy must be supplied to overcome the forces holding the bonded atoms together.
Why does forming a chemical bond release energy?
The bonded arrangement is more stable than the separate atoms.
How do bond breaking and bond forming determine a reaction’s overall energy change?
The overall change depends on the energy taken in to break reactant bonds and the energy released when product bonds form.