Chemistry — Energetics

Exam board: CCEA  |  Back to subjects

Board-Specific Note

CCEA specification; taken in Northern Ireland.

Learning Objectives

• Define enthalpy changes
• Use Hess's law
• Compute bond enthalpies

Key Points

• Enthalpy change ΔH
• Hess's law: path independent
• ΔH = Σ(bonds broken) − Σ(bonds formed)

Lesson Plan (50 minutes)

1. Starter (5 min): Recall prior knowledge of energetics with quick questions.
2. Teaching (15 min): Work through each of the learning objectives, explaining principles step by step.
3. Key points review (5 min): Revisit the key points together, confirming understanding.
4. Worked example (10 min): Model the example question: Is an exothermic reaction ΔH positive or negative?. Solution: Negative (heat released)
5. Practice (10 min): Students attempt the practice questions independently; circulate and support.
6. Plenary (5 min): Review answers and address misconceptions.

Homework

• Define standard enthalpy of formation
• Sketch an exothermic energy profile
• Compute ΔH from bond energies

Assessment

Check practice answers against the model answer; use the built-in practice questions as formative assessment.