Chemistry study notes
Chemical Energetics
Explain temperature changes and the energy cost of rearranging particles.
O-Level 6092 (2026) / SEC G3 K324 (2027)
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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.
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Scope
Learning outcomes
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