Isomerism

• Structural isomers are molecules with the same molecular formula but a different structural formula
• Stereoisomers are molecules with the same structural formula but a different arrangement of atoms in space
• Explain why the boiling point of a molecule is lower than of its straight chain isomer

  It has a smaller surface area and so has weaker Van der Waals forces
• Isomerism occurs when molecules ae made out of the same number and type of atoms but their atoms are arranged differently
• There are three types of structural isomerism: chain, position and functional group isomerism
• Chain isomerism only occurs when branching happens
• Position isomerism is where the same functional group is moved along the chain to a different position
• Functional group isomerism occurs when the functional group of a molecule is different in two isomers
• alkenes and cycloalkanes are functional group isomers
• aldehydes and ketones are functional group isomers
• Stereoisomerism occurs when molecules have the same structural formula but a different arrangement of atoms in space
• There are two types of stereoisomerism: geometrical isomerism and optical isomerism
• A C=C has restricted rotation
• When an alkene has two different groups attached to each end of the C=C, geometrical isomerism occurs