Seneca
Sign up

Empirical Formulae

Chemistry: AQA GCSE Higher, topic 2.1.5

Empirical Formulae

You can work out the proportion of each ion in a compound. The empirical formula of an ionic compound is the simplest ratio of ions possible.

Ca2+ and F-

Ca2+ and F-

  • In order for the charges to balance out and for the overall formula to be neutral, there must be 2 F- ions for each Ca2+ ion.
  • The empirical formula is CaF2
Na+ + SO42-

Na+ + SO42-

  • In order for the charges to balance out and for the overall formula to be neutral, there must be 2 Na+ ions for each SO42- ion.
  • The empirical formula is Na2SO4.

Test yourself on Empirical Formulae

  • If an ionic compound contained Mg2+ and O2- ions, what would the empirical formula be?

  • Which of the following is the correct empirical formula?

  • What are the three steps used to work out the empirical formula of an ionic compound?

  • If a compound contained Ca2+ ions and Cl- ions, what would the empirical formula be?

Practise this topic for free