Definition. - A monobasic organic acid, CCl3.COOH, usually obtained by the oxidation of hydrated chloral with nitric acid.

Description and Properties. - White, deliquescent, rhombohedral crystals, having a slight, characteristic, mildly pungent odor. Very soluble in water and alcohol; in the latter, part of the acid is changed into the ester. The aqueous solution on boiling is decomposed with the formation of chloroform and carbon dioxide: CCl3COOH = CHCl3 + C02.

10 parts of trichloracetic acid and 1 part of water form a liquid known as acidum trichloraceticum liquefactum; it is often dispensed in this form. (See Phenol Lique-factum).

It precipitates proteids and is used as a reagent for the detection of albumin in urine and milk.

Trichloracetic acid is far stronger than acetic acid and should be used with great caution.