Demonstration of iodoform

Chemicals needed

distilled water

ethanol GSLEICHT.gif (932 Byte) F    R 11    S (2)-7-16

(or denatured alcohol)

iodine  GSGESUND.gif (476 Byte) Xn  GSUMWELT.gif (758 Byte) N   R 20/21-50    S (2)-23-25-61

sodium carbonate (or hydrate) GSGESUND.gif (476 Byte) Xi   R 36    S (2)-22-26

instead of ethanol one can also use most of the other organic molecules containing a methyl group which borders on a alcohol, aldehyde, ketone or carboxylic acid function.

Equipment needed

test tube
burner (preferably alcohol-)

Test procedure


One can save the iodoform for further experiments, or dispose of it as halogen-containing organic waste. The solution can be disposed in the drainage.


The reaction, the mechanics of which are not completely clear, but which in any case involve an oxidation of alcohol, etc. into carboxylic acid, was previously used for the structural determination of organic molecules.


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During the reaction iodine dissolves and is rapidly transformed.

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After the reaction the solution clarifies and iodoform is deposited.


Described in numerous organic and pharmaceutical lab exercises. Use of sodium carbonate derived from 1574 L, "Jodoform", p. 295, [2].