Test for Phenol

Reaction of Phenol with neutral Ferric Chloride

Phenol reacts with neutral ferric chloride to give a violet coloured water soluble complex.

C6H5OH + FeCl3 --------------> [Fe(OC6H5)6]3- + 3H+ + 3HCl

The complex formed is a coordination compound in which iron is hexacovalent. In fact, all compounds, whether aliphatic or aromatic containing the enol group (C=C-OH) but unlike alcohol give characteristics colours with neutral FeCl3. Different phenols give different colour. This reaction forms the basis of group test for the enolic grouping and may also be used to disitnguish between different phenols on the basis of the colour obtained.

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