1. CHEMICAL FORMULAE & EQUATIONS 3.5 Chemical Formulae

2. At the end of this lesson, you should be able to: 3.5 Chemical Formulae 1.State the meaning of chemical formula. 2.State the meaning of empirical formula. 3.State the meaning of molecular formula. 4.Determine empirical & molecular formula of substances. 5.Compare and contrast empirical formula with molecular formula. 6.Solve numerical problems involving empirical & molecular formula.

3. 3.5 Chemical Formulae Empirical Formula Molecular Formula Calculation & Determination Chemical Formula Numerical Problems

4. Copper (II) Sulphate 3.5 Chemical Formulae Representation of a chemical substance using letters for atoms and subscript numbers to show the numbers of each type of atoms that are present in the substance. CuSO 4 Chemical Formula

5. 3.5 Chemical Formulae Information from chemical formula All the elements present in the compound Number of atoms of each element Calculate M r or Relative Formula Mass

6. 3.5 Chemical Formulae Formula that shows the simplest whole number ratio of atoms of each element in the compound Empirical Formula ElementsXY Mass (g) or % of element No. of moles of atoms Ratio of moles Simplest ratio of moles

7. 3.5 Chemical Formulae Molecular Formula Formula that shows the actual number of atoms of each element that are present in the compound Molecular Formula = ( Empirical Formula )n