Chemistry study notes
Chemical Energetics
Explain temperature changes and the energy cost of rearranging particles.
O-Level 6092 (2026) / SEC G3 K324 (2027)
Choose a topic
4 topicsFollow the energy transfer
A temperature change is evidence about the surroundings.
Investigate an energy change
Make the measurement large enough to interpret fairly.
Read an energy profile
The barrier and the overall change are different quantities.
Pure onlyBreaking bonds costs energy; making bonds releases it
The net change depends on both parts of the rearrangement.
Pure only
Scope and references
Learning outcomes and sources
9. Chemical Energetics (6092 / K324). Use the outcome map to find the explanation for a particular syllabus requirement.
See the learning outcome map
9(a) Explain enthalpy-change sign
- Exothermic negative dH
- Endothermic positive dH
9(b) Represent energy profiles
- Reactant/product levels
- Activation energy
- Reaction enthalpy change
9(c) Explain bond-breaking/making energy
- Breaking endothermic
- Making exothermic
9(d) Explain overall enthalpy qualitatively
- Compare breaking and making covalent bonds
- 2026 Pure Chemistry 6092
Official topic 9, pages 19. Original explanations mapped to the stated outcomes; 2026 and 2027 topic content agrees.
- 2027 Pure Chemistry K324
Official topic 9, pages 19. Original explanations mapped to the stated outcomes; 2026 and 2027 topic content agrees.
- 2026 Combined Chemistry 5086 / 5088
Official topic 9, pages 33. Original explanations mapped to the stated outcomes; 2026 and 2027 topic content agrees.
- 2027 Combined Chemistry K326 / K328
Official topic 9, pages 33. Original explanations mapped to the stated outcomes; 2026 and 2027 topic content agrees.
- Grail: 6092 Chemistry Complete Notes, Version 1
Background consultation: Chapter 16, energy profiles, pp. 68-70. Teaching additions and examples are original; syllabus scope and chemistry independently checked.