Stoichiometry
Stoichiometry — Formulae Sheet (Tabular Form)
| Concept | Formula | Units | Key Notes |
|---|---|---|---|
| Number of Moles | n = m / M | mol | m = mass (g), M = molar mass (g mol⁻¹) |
| Mass from Moles | m = n × M | g | Direct conversion |
| Moles from Particles | n = N / Nₐ | mol | Nₐ = 6.02 × 10²³ |
| Number of Particles | N = n × Nₐ | particles | Atoms, ions, molecules |
| Molar Mass | M = Σ Aᵣ | g mol⁻¹ | Sum of atomic masses |
Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 11 World Records and 7 Distinctions, Educate A Change O Level And IGCSE Chemistry Full Scale Course
| Concept | Formula | Units | Key Notes |
|---|---|---|---|
| Gas Volume (RTP) | V = n × 24 | dm³ | 1 mol gas = 24 dm³ |
| Moles from Gas Volume | n = V / 24 | mol | Volume in dm³ |
| Ideal Gas Equation | PV = nRT | Pa, m³, mol, K | R = 8.31 J mol⁻¹ K⁻¹ |
| Rearranged Gas Equation | n = PV / RT | mol | Used in calculations |
| Molar Volume (STP) | 1 mol = 22.4 dm³ | dm³ | Standard conditions |
Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 11 World Records and 7 Distinctions, Educate A Change O Level And IGCSE Chemistry Full Scale Course
| Concept | Formula | Units | Key Notes |
|---|---|---|---|
| Concentration | C = n / V | mol dm⁻³ | V in dm³ |
| Moles in Solution | n = C × V | mol | Core formula |
| Mass Concentration | C = m / V | g dm⁻³ | Alternative form |
| Dilution Formula | C₁V₁ = C₂V₂ | mol dm⁻³, dm³ | Used in dilution problems |
Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 11 World Records and 7 Distinctions, Educate A Change O Level And IGCSE Chemistry Full Scale Course
| Concept | Formula | Units | Key Notes |
|---|---|---|---|
| Percentage Yield | % yield = (actual yield / theoretical yield) × 100 | % | Efficiency of reaction |
| Percentage Purity | % purity = (pure mass / total mass) × 100 | % | Impurity calculation |
| Atom Economy | Atom economy = (Mr of desired product / total Mr of products) × 100 | % | Green chemistry concept |
| Limiting Reagent | Based on smallest mole ratio | — | Determines product amount |
Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 11 World Records and 7 Distinctions, Educate A Change O Level And IGCSE Chemistry Full Scale Course
| Concept | Formula | Units | Key Notes |
|---|---|---|---|
| Mole Ratio | From balanced equation | — | Use coefficients |
| Mass Ratio | Based on mole ratio × molar mass | — | Convert to mass |
| Volume Ratio (Gases) | Volume ∝ moles | — | Same T and P |
| Empirical Formula | Simplest whole number ratio | — | From mole ratios |
| Molecular Formula | Molecular = n × empirical | — | n = Mᵣ / empirical mass |
Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 11 World Records and 7 Distinctions, Educate A Change O Level And IGCSE Chemistry Full Scale Course