Edexcel IGCSE Chemistry 1.32 empirical and molecular formulae

Practise formula-definition questions by reducing molecular formulae to simplest ratios and explaining empirical formula wording.

Exam points

Explain empirical formula as the simplest whole-number ratio of atoms in a compound.
Reduce molecular formulae such as hydrocarbons to decide whether the empirical formula matches.

[Maximum number: 2]

Ocimene is an organic compound that gives some plants their particular smell.
The molecular formula of ocimene is $\mathrm{C}_{10} \mathrm{H}_{16}$

Using ocimene as an example, explain what is meant by the term empirical formula.

M1 simplest (whole number) ratio of atoms present (in a compound)

M2 empirical formula (of ocimene/ $\mathrm{C}_{10} \mathrm{H}_{16}$ ) is $\mathrm{C}_{5} \mathrm{H}_{8}$

ALLOW elements for atoms

ALLOW C : H ratio 5:8

All question bank results loaded

1.32 Empirical and molecular formulae question 1