Reaction Summary
Reagents
- Aqueous iodine,
- Aqueous sodium hydroxide,
Conditions
- Warm
Catalyst
- None
Chemical Equation
Equation
By-Products
- Methanoate ion
- Iodide ion
Observations
Observations
- Pale yellow precipitate of tri-iodomethane
(antiseptic smell)
⚠️ 9701 Exam Notes / Pitfalls
Warning
- The iodoform (tri-iodomethane) test: positive for
groups and for (which is first oxidised to ). - Ethanal is the only aldehyde that gives a positive result.
- The
bond next to C=O is broken: the chain loses one carbon ( ➔ ). - Mechanism is not required at 9701 — describe it as substitution of the three CH₃ hydrogens by I, then hydrolysis/cleavage of the C–C bond.