C11: Energetics, Thermochemistry, Calorimetry and Hess’s Law
Official Cambridge & Imperial ESAT specification requirements for Energetics, Thermochemistry, Calorimetry and Hess’s Law on the Chemistry paper. Understand the syllabus boundaries, spot distractor traps engineered by examiners, and master the 2-step Sub-90 shortcuts that compress solve time well below the 88.8-second cutoff.
Official Syllabus Subtopics
Requirements specified in the UAT-UK framework
- 1Exothermic (ΔH < 0, heat released) and endothermic (ΔH > 0, heat absorbed) reactions
- 2Reaction profile diagrams: reactants, activation energy peak, products
- 3Calorimetry heat equation: q = m c ΔT and molar enthalpy ΔH = -q / n
- 4Bond energies: ΔH = sum(Bonds Broken) - sum(Bonds Formed)
- 5Hess’s Law energy conservation cycles and formation/combustion pathways
Sub-90 Exam Speed Tips
How top candidates solve this spec under the 88.8s clock
Remember "MEXO BENDO": Making bonds is EXOthermic (ΔH < 0), Breaking bonds is ENDOthermic (ΔH > 0).
In calorimetry calculations, always check the negative sign: ΔH = -q / n.
Examiners engineer distractor options using common algebraic expansions and sign slips. Always test structural ratios or invariants before calculating arithmetic values.
Tested Topics in Specification C11
Master the individual question patterns and Sub-90 shortcuts for this specification.
Calorimetry (q = mcΔT, ΔH = -q/n), Hess's Law Cycles & Mean Bond Enthalpies (ΣE(broken) - ΣE(formed))
For bond energies: ΔH = Broken (Left) - Formed (Right); cancel any bonds that remain unchanged on both sides before multiplying. In q = mcΔT, m is ALWAYS the mass of water/total aqueous solution being heated.
Ready to Master Specification C11 Under Exam Conditions?
Practice timed questions under the authentic Pearson VUE interface with live split stopwatch pacing, dry-wipe scratchpad, and distractor forensics.