Key definitions
Mole The amount of substance in grams that has the same number of particles as there are atoms in 12grams of carbon-12
Ar Relative atomic mass is the average mass of one atom compared to one twelfth of the mass of one atom of carbon-12
Mr Relative molecular mass is the average mass of a molecule compared to one twelfth of the mass of one atom of carbon-12
Empirical formula Simplest whole number ratio of atoms of each element in the compound
Molecular formula The actual number of atoms of each element in the compound
3.1.2 Amount of substance quick check
Exam questions
Check your units with this handy conversion cube cm3 dm3 and m3
Use this equation to calculate the amount in moles of a solid
Concentration equations - use these to calculate the amount in moles of a substance dissolved in solution
Empirical formula Simplest whole number ratio of atoms of each element in the compound
How to calculate the empirical formulae of a compound