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3.2.10—Reduction of organic functional groups

Syllabus
First assessment 2025
Objective
3.2.10
Level
HL

Reduction of Carbonyl Compounds

A carboxylic acid can be reduced through an aldehyde to a primary alcohol; a ketone is reduced to a secondary alcohol. Hydride ions supply the reduction equivalent in these transformations.

Track the carbon functional group rather than only the reagent: an aldehyde gives a primary alcohol and a ketone gives a secondary alcohol. Hydride supplies an electron-rich H unit to the carbonyl carbon; named reducing agents and detailed mechanisms are outside this objective.

Deducing Reduction Products

Assessment in practice

Representative question

Question 1

[Maximum number: 1]

Which product may be obtained by the reduction of CH3CH2COOH\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH} ?

A

CH3CH(OH)CH3\mathrm{CH}_{3} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{3}

B

CH3CH2CH2OH\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}

C

CH3CH2OCH3\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OCH}_{3}

D

CH3COOCH3\mathrm{CH}_{3} \mathrm{COOCH}_{3}

Electron Transfer Reactions Summary

Retrieve the route: assign oxidation states, balance half-equations, predict displacement, label cells, trace electrons and ions, follow organic redox pathways, calculate potentials and choose electrolysis products.

Check electron loss/gain, anode/cathode versus polarity, spontaneous sign, salt-bridge direction, ions present, organic functional-group direction and object-cathode placement.