Chapter summary
Chemical Calculations, at a glance
Turn formulae, measurements and equations into defensible numerical answers.
O-Level 6092 (2026) / SEC G3 K324 (2027)
Quick revision
Revisit the essentials, then return to an explanation when you need it.
- Formula and equation
Balance before calculating.
- Known quantity to moles
n = m/M; n = cV; n = V/24 at room conditions.
- Mole ratio
Use coefficients, including the limiting reactant.
- Requested quantity
Convert moles and include units.
Pure only
For ionic equations conserve charge as well as atoms. For concentration use dm3. Percent composition, empirical/molecular formulae, yield and purity are Pure extensions.