Specification Point 9.32C:
Recall members of a given homologous series have similar reactions because their molecules contain the same functional group and use this to predict the products of other members of these series
- Homologous series are families or groups of organic compounds that have similar features and chemical properties due to them having the same functional group.
- All members of a homologous series have:
- The same general formula.
- The difference in the molecular formula between one member and the next is CH2.
- Gradation in their physical properties.
- Same functional group.
- Similar chemical properties.
- The chemistry of homologous series is therefore determined by the functional group.
- We can use this to predict how molecules further down a homologous series will react.
- For example we know that ethene will decolourise bromine water, so we can predict that hexene and septene will do the same, even though they are bigger molecules.
- This is due the the alkene functional group, the C=C double bond, which is present in all alkenes.
Edexcel GCSE Chemistry Notes
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