This topic summary covers Topic Summary: Bond Energies within Bond Energies (HT) for GCSE Chemistry. Revise Bond Energies (HT) in Energy Changes for GCSE Chemistry with 20 exam-style questions and 15 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 13 of 13 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 13 of 13
Practice
20 questions
Recall
15 flashcards
Topic Summary: Bond Energies
Key Terms
- Bond energy — energy to break 1 mol of a bond (kJ/mol)
- ΔH — energy in (breaking) minus energy out (making)
- Breaking bonds — endothermic (requires energy)
- Making bonds — exothermic (releases energy)
Must-Know Facts
- Breaking bonds ALWAYS requires energy (endothermic)
- Making bonds ALWAYS releases energy (exothermic)
- ΔH = Σ(breaking) − Σ(making)
- Negative ΔH → exothermic; Positive ΔH → endothermic
- Double/triple bonds have higher bond energies
- Count ALL bonds × stoichiometric coefficients