Organic Functional Groups — Flashcards & Quiz

Key Points

• Alcohols (–OH): polar, hydrogen-bonding, classify as primary, secondary or tertiary based on the carbon bearing the OH.
• Aldehydes (–CHO): C=O at the end of a chain. Oxidation of a primary alcohol gives an aldehyde.
• Ketones (–C(=O)–): C=O in the middle of a chain. Oxidation of a secondary alcohol gives a ketone (which resists further oxidation).
• Carboxylic acids (–COOH): acidic. Full oxidation of a primary alcohol or aldehyde gives a carboxylic acid.
• Esters (–COO–): form from carboxylic acid + alcohol via Fischer esterification; characteristic sweet smells.
• Amines (–NH₂) and amides (–CONH₂): nitrogen-containing; amines are basic, amides form peptide bonds in proteins.

Common Mistakes to Avoid

1. Confusing aldehydes (C=O at the end) with ketones (C=O in the middle).
2. Claiming tertiary alcohols can be oxidised — they can't (no H on the C bearing OH).
3. Mixing up IUPAC priority: carboxylic acid > ester > amide > aldehyde > ketone > alcohol > amine.
4. Writing the ester linkage backwards — the O comes from the alcohol, the C=O from the acid.
5. Forgetting that amines are basic and carboxylic acids are acidic — they react together to form amides (peptide bonds).

Exam Strategy

VCAA Unit 4 AOS 1 functional group questions ask you to identify groups, predict reactions, or name structures. Method: (1) identify all functional groups in the structure, (2) assign the highest-priority one as the principal for naming, (3) predict reactivity based on the group, (4) write balanced equations for expected reactions (oxidation, esterification, etc.).

Revision Tip

Functional group recognition is visual — drill a Revizi flashcard deck with structures on one side and group names on the other, varying direction.

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