Iodoform  -  CHI3



This is a small sample of iodoform, prepared from a solution of KI, and excess mix of dilute H2O2 and HCl, from which first iodine was made as a coarse flocculent precipitate. This iodine was rinsed with water two times. Next it was converted to iodoform by adding quite some water, excess acetone and just enough solution of NaOH. The iodoform, thus formed, was extracted with ether and dried by blowing hot air over the etherial solution (approximately 50 C). The amount, shown here is approximately 1 gram. The extraction with ether assures that any ionic impurities (e.g. NaOH or iodide-salt, co-precipitated with the iodoform from the aqueous solution) are left behind in the aqueous layer.

Iodoform is a moderately stable compound, which easily looses iodine. The compound has a very peculiar pungent 'hospital-like' smell.

The picture below shows the contents of the little vial, shown from above:

Remark: The sample of iodoform has some pieces, which are a little brown. This is due to the heating at 50 C. Apparently, iodoform easily decomposes, giving iodine, which causes the brown color. Still, this iodoform is quite pure and it is expected to be better than 99+ %.