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Cambridge Chemistry Challenge (C3L6)
C3L6 is for Year 12 students and is sat at school in the summer. It starts from AS-Level chemistry and explains unfamiliar ideas in the question itself.
Questions are long and often built around one context, with later parts dependent on earlier ones.
How to prepare here
- Case studies practise longer C3L6 questions: several linked parts that share one story.
- Multi-step questions train your accuracy and ability to carry an answer through.
- When a question explains a new idea, read it twice and try to derive its formula.
Conventions
- 3 significant figures unless the question says otherwise.
- Units: SI with dm³ and mol dm⁻³.
- Constants as on the data sheet: R = 8.314, NA = 6.022 × 10²³.
C3L6 question types (15)
- ΔG from ΔH and ΔS
- First order: concentration after time t
- Activation energy from two rate constants
- Radioactive decay: elapsed time
- pH of a weak acid
- Buffer pH (Henderson–Hasselbalch)
- Moles of an ideal gas
- Hess's law from enthalpies of formation
- Solubility from Ksp
- Mass deposited by electrolysis
- E°cell from reduction potentials
- Concentration from absorbance
- Wavelength to break a bond
- pH of benzoic acid from a weighed sample
- H₂ + I₂ ⇌ 2HI: equilibrium amounts
Book pages for this level
Plus 31 reagents to drill in the reagent trainer.