Trichloroacetic acid Formula – Structure, Properties, Uses, Sample Questions
Trichloroacetic acid consists of elements Carbon, Hydrogen, Chlorine, and Oxygen. Carbon is a nonmetallic element present in group-14 of the periodic table. Its atomic number is 6 and is represented by the symbol C. Hydrogen is the lightest, colorless, odorless, tasteless, and flammable gas. Its atomic number is 1 and is represented by the symbol H. Chlorine is toxic, a corrosive gas present in group-17 of the periodic table. It is the second lightest element in that group. Its atomic number is 17 and is represented by the symbol Cl. Oxygen is a highly reactive nonmetal present in the chalcogen group i.e., group-16. Its atomic number is 8 and is represented by the symbol O.
Trichloroacetic acid is an organic compound and an analogue of acetic acid where the three atoms of Hydrogen are replaced by Chlorine atoms. Trichloroacetic acid is discovered by Jean-Baptiste Dumas in the year 1839. The chemical formula of Trichloroacetic acid is C2HCl3O2. It is often called TCA (A short form for Trichloroacetic acid). Trichloroacetic acid in its solid form appears in crystalline solid with no color. Slowly it converts into syrup by absorbing moisture in the air. This syrup is dissolved into the water by liberating heat forms a powerful acid. It is corrosive and used as a protein precipitant in clinical chemistry.
The esters and salts of Trichloroacetic acid are called trichloroacetates. The other names for Trichloroacetic acid are Trichloroethanoic acid or Aceto-caustin. IUPAC name of this compound is Trichloroacetic acid.
Structure of Trichloroacetic acid
It is an organic covalent compound. The carbon atom which is bonded with O, OH, and CCl3 groups is sp2 hybridized. The other carbon atom which is bonded with Cl3, COOH groups is sp3 hybridized.
Physical Properties of Trichloroacetic acid
- The molecular weight of Trichloroacetic acid is 163.38 g/mol.
- The melting point of Trichloroacetic acid is 57° to 58°C.
- The boiling point of Trichloroacetic acid is 196° to 197°C.
- The density of Trichloroacetic acid is 1.63 g/cm3.
- It appears in a colorless crystalline solid.
- The odor is a pungent smell.
Chemical Properties of Trichloroacetic acid
- Trichloroacetic acid is soluble in water.
- The pH value of Trichloroacetic acid is 1.2. So it is acidic in nature.
- It is corrosive in nature.
- Trichloroacetic acid doesn’t react with water but reacts with protein.
- Strong oxidizing agent.
Preparation of Trichloroacetic acid
- Trichloroacetic acid is synthesized by reacting Acetic acid (CH3COOH) with Chlorine (Cl) in presence of a catalyst.
CH3COOH + 3Cl2 → CCl3COOH + 3HCl
- It is also produced by the oxidation of trichloroacetaldehyde.
Uses of Trichloroacetic acid
- In biochemistry, Trichloroacetic acid is used for the precipitation of macromolecules. It precipitates proteins, DNA and RNA.
- It is used for Tattoo removal.
- It is used during pregnancy for skin infections.
- Trichloroacetic acid is used in microscopy as a fixative and decalcifier.
- It is used on the skin for chemoablation of warts. In dilute form, used on genital warts as well.
- Trichloroacetic acid is used in cosmetics.
- Trichloroacetic acid is widely used in clinical chemistry in the preparation of formulations.
Question 1: Is Trichloroacetic acid a strong acid?
Yes, Trichloroacetic acid is strong acid than acetic acid, because electronegative chlorine atoms remove electron density from the carboxyl group producing a partial positive charge. So the pH value is also high i.e., pH value is 1.2
Question 2: Trichloroacetic Acid is carcinogenic?
Yes, Trichloroacetic Acid is added in suspected list of human carcinogen. It contain about 15 percent -50 percent of the carcinogenic chemicals. In animals it causes fertility and birth problems.
Question 3: Is Trichloroacetic Acid safe?
Yes, to some extent. It used for treatment of warts. Excessive usage can cause damage. It is harmful to environment.
Question 4: Find the molar mass of Trichloroacetic Acid.
Trichloroacetic Acid consists of 2 carbons, 1 hydrogen, 3 chlorine atoms and 2 oxygens.
- Atomic weight of each carbon = 12.0107
- Atomic weight of each hydrogen = 1.00784
- Atomic weight of each chlorine = 35.453
- Atomic weight of each oxygen = 15.999
Molecular weight of C2HCl3O2 = (2 × 12.0107) + (1 × 1.00784) + (3 × 35.453) + (2 × 15.999)
= 163.38 g/mol
Question 5: What are the uses of Trichloroacetic Acid?
Majorly Trichloroacetic Acid is used for the precipitation of macromolecules like proteins, DNA, and RNA. It is also used in cosmetic area. Used in chemical peel and tattoo removal procedures. Also used in treatment of warts.
Question 6: What kind of acid is Trichloroacetic Acid?
Trichloroacetic Acid is a monocarboxylic acid and an organochlorine compound.. Here the three methyl hydrogens in acetic acid are substituted by chlorine. Trichloroacetic Acid (TCA) is a carcinogenic agent and a mouse metabolite.
Question 7: What is the effect of Trichloroacetic Acid?
As Trichloro acetic acid penetrates through the skin, it causes protein coagulation and denaturation of the cells in epidermis and dermis as well as blood vessels.