Bond Energy Calculations — GCSE Chemistry Revision
Revise Bond Energy Calculations for GCSE Chemistry. Step-by-step explanation, worked examples, common mistakes and exam-style practice aligned to AQA, Edexcel, OCR, WJEC, Eduqas, CCEA, Cambridge International (CIE), SQA, IB, AP.
At a glance
- What StudyVector is
- An exam-practice platform with board-aligned questions, explanations, and adaptive next steps.
- This topic
- Bond Energy Calculations in GCSE Chemistry: explanation, examples, and practice links on this page.
- Who it’s for
- Students revising GCSE Chemistry for UK exams.
- Exam boards
- Practice is aligned to major specifications (AQA, Edexcel, OCR, WJEC, Eduqas, CCEA, Cambridge International (CIE), SQA, IB, AP).
- Free plan
- Sign up free to use tutor paths and feedback on your answers. Free access is 3 days uncapped, then 30 min practice/day. Pricing
- What makes it different
- Syllabus-shaped practice and progress tracking—not generic AI answers.
Topic has curated content entry with explanation, mistakes, and worked example. [auto-gate:promote; score=70.6]
Next in this topic area
Next step: Cells & Batteries
Continue in the same course — structured practice and explanations on StudyVector.
Go to Cells & BatteriesWhat is Bond Energy Calculations?
Bond energy (or bond enthalpy) is the amount of energy required to break one mole of a specific covalent bond. During a chemical reaction, energy is taken in to break bonds in the reactants, and energy is released when new bonds are formed in the products. The overall energy change of a reaction can be calculated by subtracting the energy released from the energy absorbed.
Board notes: Bond energy calculations are a higher-tier topic for all exam boards. They require careful, systematic working. You will always be given the necessary bond energy data in the question.
Step-by-step explanationWorked example
Calculate the energy change for H₂ + Cl₂ → 2HCl. Bond energies (kJ/mol): H-H=436, Cl-Cl=242, H-Cl=431. Bonds broken: 1 x H-H + 1 x Cl-Cl = 436 + 242 = 678 kJ. Bonds made: 2 x H-Cl = 2 x 431 = 862 kJ. Energy change = 678 - 862 = -184 kJ/mol. It is an exothermic reaction.
Practise this topic
Jump into adaptive, exam-style questions for Bond Energy Calculations. Free to start; sign in to save progress.
Common mistakes
- 1Getting the calculation the wrong way around. Remember: Energy Change = Energy in (bonds broken) - Energy out (bonds made).
- 2Forgetting to account for the number of each type of bond in the molecules. You must use the balanced chemical equation and draw out the structures if necessary.
- 3Using the wrong bond energies from the table provided in the exam question.
Bond Energy Calculations exam questions
Exam-style questions for Bond Energy Calculations with mark-scheme style solutions and timing practice. Aligned to AQA, Edexcel, OCR, WJEC, Eduqas, CCEA, Cambridge International (CIE), SQA, IB, AP specifications.
Bond Energy Calculations exam questionsGet help with Bond Energy Calculations
Get a personalised explanation for Bond Energy Calculations from the StudyVector tutor. Ask follow-up questions and work through problems with step-by-step support.
Open tutorFree full access to Bond Energy Calculations
Sign up in 30 seconds to unlock step-by-step explanations, exam-style practice, instant feedback and on-demand coaching — completely free, no card required.
Try a practice question
Unlock Bond Energy Calculations practice questions
Get instant feedback, step-by-step help and exam-style practice — free, no card needed.
Start Free — No Card NeededAlready have an account? Log in
Step-by-step method
Step-by-step explanation
4 steps · Worked method for Bond Energy Calculations
Core concept
Bond energy (or bond enthalpy) is the amount of energy required to break one mole of a specific covalent bond. During a chemical reaction, energy is taken in to break bonds in the reactants, and energ…
Frequently asked questions
Why is breaking bonds an endothermic process?
Energy is required to overcome the electrostatic forces of attraction that hold the atoms together in a bond. Therefore, you have to put energy in to break them.
Why are the calculated values sometimes different from experimental values?
The bond energies used in calculations are average values taken from a range of different compounds. The actual bond energy in a specific molecule may be slightly different.