Values printed in the exam
The values printed in every 9701 question paper, as listed in the syllabus.
| Quantity | Formula |
|---|---|
| Molar gas constant | R = 8.31 J K⁻¹ mol⁻¹ |
| Faraday constant | F = 9.65 × 10⁴ C mol⁻¹ |
| Avogadro constant | L = 6.022 × 10²³ mol⁻¹ |
| Charge on an electron | e = −1.60 × 10⁻¹⁹ C |
| Molar volume of gas | 22.4 dm³ mol⁻¹ at s.t.p.; 24.0 dm³ mol⁻¹ at room conditions |
| Ionic product of water | Kw = 1.00 × 10⁻¹⁴ mol² dm⁻⁶ at 298 K |
| Specific heat capacity of water | c = 4.18 J g⁻¹ K⁻¹ |
AS: learn these
| Quantity | Formula |
|---|---|
| Amount of substance | n = m ÷ M |
| Concentration | c = n ÷ V |
| Ideal gas equation | pV = nRT |
| Energy change | q = mcΔT, ΔH = −mcΔT ÷ n |
| Partial pressure | partial pressure = mole fraction × total pressure |
| Equilibrium constants | Kc from concentrations, Kp from partial pressures |
A Level: learn these
| Quantity | Formula |
|---|---|
| Entropy change | ΔS° = ΣS°(products) − ΣS°(reactants) |
| Gibbs free energy | ΔG = ΔH − TΔS, ΔG = −nE°cellF |
| Cell potential | E°cell = E°(positive electrode) − E°(negative electrode) |
| Nernst equation | E = E° + (0.059/z) log([oxidised] ÷ [reduced]) |
| Electrolysis | Q = It, F = Le |
| Acids | pH = −log[H⁺], Ka = [H⁺][A⁻] ÷ [HA], pKa = −log Ka |
| Rate equation | rate = k[A]ᵐ[B]ⁿ; first order: t½ = 0.693 ÷ k |
| Carbon atoms from mass spectrum | n = 100 × abundance[M+1]⁺ ÷ (1.1 × abundance M⁺) |
The syllabus data section
| Table in the syllabus | In the exam |
|---|---|
| Important values, constants and standards | Printed in the question paper |
| Periodic Table | Printed in the question paper |
| Ionisation energies, bond energies, electrode potentials | Given in questions when needed |
| Electronegativities, NMR shifts, IR absorptions | Given in questions when needed |
From our review of recent 9701 papers; check your own past papers too.
How to use this sheet
- Know the AS relationships by heart: most calculation marks depend on them.
- Watch units: dm³ vs cm³, kJ vs J, and kPa vs Pa in pV = nRT.
- Learn which relationships are not tested, e.g. the Kp–Kc relationship and Kw = Ka × Kb.
- Source: the official Cambridge syllabus (PDF). Cambridge's own booklet is copyright, so this is our own layout of the standard formulae.