Introduction

3. Formulae

3.1. Molecular Formula and Structural Formula

Molecular formula
o Shows the actual number of each type of atom in a compound
o Does not show the way the atoms are joined together

Structural formula
o Shows the arrangement of atoms within the molecule
o It shows the sequence in which the atoms are bonded to each other

	Butane	2-Methylpropane
Molecular formula	C₄H₁₀	C₄H₁₀
Structural formula	CH₃CH₂CH₂CH₃	CH(CH3)₃

	Ethanol
Molecular formula	C₂H₆O
Structural formula	CH₃CH₂OH not C₂H₅OH