4.2 understand how to represent organic molecules using empirical formulae, molecular formulae, general formulae, structural formulae and displayed formulae

Molecular formula: shows actual number of atoms in a molecule
Empirical formula: shows the simplest ratio of atoms in a compound
General formula: shows relationship of homologous series, is an equation to calculate the number of atoms. (e.g. alkanes is C_nH_2n+2, alkenes is C_nH_2n)
Structural formula: shows how atoms in a molecule are joined together
Displayed formula: full structural formula, shows all bonds in a molecule as individual lines

These are different formulas for Butane:
Displayed formula:




Structural formula: CH₃ – CH₂ – CH₂ – CH₃
Molecular formula: C₄H₁₀
Empirical formula: C₂H₅
General formula: Because it is an alkane, the general formula is C_nH_2n+2.