Chemistry A-Level
Longest-chain selection
What Longest-chain selection means in Chemistry A-Level, as defined for OCR.
Definition of Longest-chain selection
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Reference: OCR
Finding the longest carbon chain containing the principal functional group, which gives the stem such as meth-, eth-, prop- or but-.
Topics that use Longest-chain selection
- Basic concepts of organic chemistry (OCR A-Level)
Related terms
- Alphabetical ordering of substituents
- Aromatic compound
- carboxyl group
- Characteristic reactions
- Condensed notation with brackets and subscripts
- Contrast with heterolytic fission
- Curly arrow notation
- delocalised electrons
Using Longest-chain selection in the exam
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