29.1 A2 Level

Formulas, functional groups and the naming of organic compounds

Cambridge A-Level Chemistry (9701)  · Unit 29: An introduction to A Level organic chemistry  · 8 flashcards

Formulas, functional groups and the naming of organic compounds is topic 29.1 in the Cambridge A-Level Chemistry (9701) syllabus , positioned in Unit 29 — An introduction to A Level organic chemistry , alongside Characteristic organic reactions.  In one line: A functional group is a specific group of atoms within a molecule that is responsible for the characteristic chemical reactions of that molecule. Examples include hydroxyl (-OH) in alcohols and carboxyl (-COOH) in carboxylic acids.

Marked as A2 Level: examined at A Level in Paper 4 (A Level Structured Questions) and Paper 5 (Planning, Analysis and Evaluation). It is not tested on the AS-only papers (Papers 1, 2 and 3).

The deck below contains 8 flashcards — 1 definition and 7 key concepts — covering the precise wording mark schemes reward.  Use the definition card to lock down command-word answers (define, state), then move on to the concept and calculation cards to handle explain, describe, calculate and compare questions.

Key definition

Functional group in organic chemistry

A functional group is a specific group of atoms within a molecule that is responsible for the characteristic chemical reactions of that molecule. Examples include hydroxyl (-OH) in alcohols and carboxyl (-COOH) in carboxylic acids.

What the Cambridge 9701 syllabus says

Official 2025-2027 spec · A2 Level

These are the exact learning outcomes Cambridge sets for this topic. The candidate is expected to be able to do each of these on the relevant paper.

  1. understand that the compounds in the table on page 47 contain a functional group which dictates their physical and chemical properties
  2. interpret and use the general, structural, displayed and skeletal formulas of the classes of compound stated in the table on page 47
  3. understand and use systematic nomenclature of simple aliphatic organic molecules (including cyclic compounds containing a single ring of up to six carbon atoms) with functional groups detailed in the table on page 47, up to six carbon atoms (six plus six for esters and amides, straight chains only for esters and nitriles)
  4. understand and use systematic nomenclature of simple aromatic molecules with one benzene ring and one or more simple substituents, for example 3-nitrobenzoic acid or 2,4,6-tribromophenol

Cambridge syllabus keywords to use in your answers

These are the official Cambridge 9701 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.

functional group skeletal formula systematic nomenclature aromatic molecules benzene ring

Tips to avoid common mistakes in Formulas, functional groups and the naming of organic compounds

Definition Flip

What is a functional group in organic chemistry?

Answer Flip

A functional group is a specific group of atoms within a molecule that is responsible for the characteristic chemical reactions of that molecule. Examples include hydroxyl (-OH) in alcohols and carboxyl (-COOH) in carboxylic acids.

Key Concept Flip

Draw the structural formula for butan-2-ol.

Answer Flip

CH3-CH(OH)-CH2-CH3. The '2' indicates that the hydroxyl group (-OH) is attached to the second carbon atom in the butane chain.

Key Concept Flip

Draw the displayed formula for pentanal.

Answer Flip

H | H-C-C-C-C-C=O | | | | | H H H H H

Key Concept Flip

What is the skeletal formula of 3-methylhexane?

Answer Flip

A zig-zag line with six points representing the carbon chain, and a methyl group (one line) branching off the third carbon.

Key Concept Flip

Give the systematic name for the compound with the structural formula CH3CH2COOCH3.

Answer Flip

Methyl propanoate. It is an ester derived from propanic acid and methanol.

Key Concept Flip

Name the compound with the formula CH3CH2CH2CN, using systematic nomenclature.

Answer Flip

Butanenitrile. The 'nitrile' suffix indicates the presence of the -CN functional group, and 'butane' indicates a four-carbon chain.

Key Concept Flip

Draw the skeletal formula of 2,4-dimethylpentane.

Answer Flip

A zig-zag line representing the five-carbon pentane chain, with single lines branching off the second and fourth carbons, representing the two methyl groups.

Key Concept Flip

What is the systematic name for the aromatic compound with a benzene ring and a nitro group at the 3rd position?

Answer Flip

3-nitrobenzene or meta-nitrobenzene. The '3-' or 'meta-' prefix indicates the position of the nitro group relative to the point of attachment to the benzene ring (if only one substituent).

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More topics in Unit 29 — An introduction to A Level organic chemistry

Formulas, functional groups and the naming of organic compounds sits alongside these A-Level Chemistry decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.

Key terms covered in this Formulas, functional groups and the naming of organic compounds deck

Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.

Functional group in organic chemistry

How to study this Formulas, functional groups and the naming of organic compounds deck

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