Empirical
and Molecular
Formulae
This AQA 3.1.2 section explains how formulas show chemical composition. Students learn the difference between empirical formula and molecular formula, how to calculate empirical formula from mass or percentage composition, and how to use relative molecular mass to find the molecular formula.
Revision Notes
Work through empirical and molecular formulae in a structured AQA sequence.
Formula
Empirical Formula
Calculating the simplest whole number ratio of atoms from composition by mass or percentage by mass.
Start revisingFormula
Molecular Formula
Using the empirical formula and relative molecular mass to find the actual number of atoms in a molecule.
Start revising3.1.2.4 Empirical and Molecular Formula – AQA A Level Chemistry
The following AQA specification points outline the knowledge and skills students are expected to demonstrate for empirical and molecular formulae.
3.1.2.4 Empirical and molecular formula
3.1.2.4 Empirical and Molecular Formula – AQA A Level Chemistry
The following AQA specification points outline the knowledge and skills students are expected to demonstrate for empirical and molecular formulae.
3.1.2.4 Empirical and molecular formula
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