Empirical formula
What Empirical formula means in Chemistry A-Level, as defined for AQA, OCR.
Definitions of Empirical formula
Exam boards and our study guides word this term in slightly different ways. Learn the version your board uses.
Check what you remember
Read the wording for your board, then hide it and explain Empirical formula in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: OCR
The simplest whole-number ratio of atoms in a compound, obtained by dividing every mole value by the smallest to obtain the ratio.
Gives the simplest whole-number ratio of atoms, found by dividing the atom ratio by its highest common factor.
The formula calculated from the percentage by mass of each element in a compound.
The simplest whole number ratio of atoms of each element present in a compound.
The simplest whole number ratio of atoms of each element in a compound.
The simplest whole-number ratio of atoms of each element in a compound.
Topics that use Empirical formula
- Empirical and molecular formula (AQA A-Level)
- Amount of substance (OCR A-Level)
- Analytical techniques (OCR A-Level)
- Basic concepts of organic chemistry (OCR A-Level)
Related terms
- Molecular formula
- Absorption and re-emission of infrared radiation
- Absorption of infrared radiation
- Absorption of infrared radiation by bond vibrations
- Alphabetical ordering of substituents
- amount of substance
- Aromatic compound
- atom economy
Using Empirical formula in the exam
Check the command word and mark scheme for your exact question. After comparing your explanation with the reference, use the term in an answer on the linked topic. This practice does not predict an exam mark.
Practise Chemistry questions
Create a free account to answer exam-style questions on this topic and get feedback on your answers.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge