Mechanism Lab
Every AQA A-level organic mechanism — but you draw the curly arrows yourself, exactly like the exam. Instant mark-scheme feedback. 3 of 16 mechanisms free without an account · all 16 with a free account.
Mechanism questions
Every curly-arrow step as a standalone drill — filter by topic, mechanism or difficulty, or start a shuffled quiz.
Synthesis Navigator
Plan a multi-step route from a start material to a target, one reagent at a time.
Free-radical substitution
Electrophilic addition
Electrophilic addition — HBr
HBr · room temperature
Electrophilic addition — bromine
Br2 (bromine water or in an organic solvent) · room temperature
Electrophilic addition — concentrated H2SO4
concentrated H2SO4 · cold
Nucleophilic substitution & elimination
Nucleophilic substitution — hydroxide ions
NaOH or KOH (aqueous) · warm, aqueous
Nucleophilic substitution — cyanide ions
KCN in aqueous ethanol · warm
Nucleophilic substitution — excess ammonia
excess NH3 in ethanol · heated in a sealed tube
Elimination — hydroxide ions
KOH in ethanol · hot, ethanolic
Further substitution of amines (2° → 3° → quaternary)
amine + bromoethane · excess haloalkane (use excess ammonia to favour the 1° amine)
Alcohol & acid-catalysed chemistry
Carbonyl & aromatic chemistry
Nucleophilic addition — cyanide (hydroxynitriles)
KCN, then dilute acid (H₂SO₄) · room temperature
Nucleophilic addition — NaBH₄ (reduction to alcohols)
NaBH₄ in water/methanol · room temperature
Nucleophilic addition–elimination — acyl chlorides
ethanoyl chloride + water / alcohol / ammonia / amine · room temperature
Electrophilic substitution — nitration of benzene
conc HNO₃ + conc H₂SO₄ · ≈50 °C (warm)
Electrophilic substitution — Friedel–Crafts acylation
ethanoyl chloride + AlCl₃ (catalyst) · heat under reflux, anhydrous
Prefer one step at a time? Drill the mechanism questions — every curly-arrow step as its own question, with a shuffled quiz mode.
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