Energy ChangesKey Facts

Key Facts: Bond Energies

Part of Bond Energies (HT)GCSE Chemistry

This key facts covers Key Facts: 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 8 of 13 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 8 of 13

Practice

20 questions

Recall

15 flashcards

📌 Key Facts: Bond Energies

  • Bond energy = energy needed to break 1 mole of a particular bond
  • Units are kJ/mol (kilojoules per mole)
  • Breaking bonds is ALWAYS endothermic (requires energy)
  • Making bonds is ALWAYS exothermic (releases energy)
  • If breaking > making: reaction is endothermic, ΔH positive
  • If making > breaking: reaction is exothermic, ΔH negative
  • Double bonds (C=C, O=O) have higher bond energy than single bonds
  • Triple bonds (N≡N) are even stronger

Keep building this topic

Read this section alongside the surrounding pages in Bond Energies (HT). That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Bond Energies (HT)

Which statement correctly describes the energy change when chemical bonds are broken?

  • A. Energy is released to the surroundings
  • B. Energy is absorbed from the surroundings
  • C. No energy change occurs
  • D. Energy may be released or absorbed depending on the bond
1 markfoundation

Explain how you would determine, from a bond energy calculation, whether a reaction is exothermic or endothermic.

2 marksstandard

Quick Recall Flashcards

What is bond energy?
The energy needed to break 1 mole of a particular bond
What are the units for bond energy?
kJ/mol (kilojoules per mole)

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