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Trichloroacetic acid

Trichloroacetic acid
IUPAC name Trichloroacetic acid
CAS number 76-03-9
RTECS number AJ7875000
Molecular formula CCl3COOH
Molar mass 163.4 g/mol
Appearance white solid
Density 1.63 g/cm³, solid
Melting point

57 °C

Boiling point

196 °C

Solubility in water very good
Acidity (pKa) 0.77
Dipole moment 3.23 D
EU classification Corrosive C)
Dangerous for
the environment (N)
R-phrases R35, R50/53
S-phrases (S1/2), S26, S36/37/39,
S45, S60, S61
Related Compounds
Related chloroacetic acids Chloroacetic acid
Dichloroacetic acid
Related compounds Acetic acid
Trifluoroacetic acid
Tribromoacetic acid
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Trichloroacetic acid (also known as trichloroethanoic acid) is an analogue of acetic acid in which the three hydrogen atoms of the methyl group have all been replaced by chlorine atoms. It is a strong acid, comparable to sulfuric acid.

It is prepared by the reaction of chlorine with acetic acid in the presence of a suitable catalyst.

CH3COOH + 3Cl2 → CCl3COOH + 3HCl

It is widely used in biochemistry for the precipitation of macromolecules such as proteins, DNA and RNA. Its sodium salt is used as a weedkiller. Solutions containing trichloroacetic acid as an ingredient are used for tattoo removal and the treatment of warts, including genital warts. It is considered safe for use for this purpose during pregnancy[1].

Salts of trichloroacetic acid are called trichloroacetates. Reduction of trichloroacetic acid results in dichloroacetic acid, a pharmacologically active compound that shows promise for the treatment of cancer[2].


The discovery of trichloroacetic acid by Jean-Baptiste Dumas in 1840 delivered a striking example to the slowly evolving theory of organic radicals and valences.[3] The theory was contrary to the beliefs of Jöns Jakob Berzelius, starting a long dispute between Dumas and Berzelius.[4]

See also


  1. ^ Wiley DJ, et al. (2002). External genital warts: Diagnosis, treatment, and prevention. Clinical Infectious Diseases, 35(Suppl 2): S210–S224
  2. ^ The Carcinogenic Potency Database (CPDB)
  3. ^ Dumas (1840). "Trichloroacetic acid". Annalen der Chemie XXXII: 101.
  4. ^ William Albert Noyes (1927). "Valence". Proceedings of the American Philosophical Society 66: 287-308.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Trichloroacetic_acid". A list of authors is available in Wikipedia.
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