Chloroacetic acid is a chemical compound with the formula CH₂ClCOOH. It is used in various industrial applications, including the production of dyes, pharmaceuticals, and herbicides.
| IUPAC Name | Chloroacetic acid |
| Molecular Formula | CH₂ClCOOH |
| CAS Number | 79-11-8 |
| Synonyms | Monochloroacetic acid, MCA, Chloroethanoic acid, Chloroethylic acid |
| InChI | InChI=1S/C2H3ClO2/c3-1-2(4)5/h1H2,(H,4,5) |
Chloroacetic Acid Properties
Chloroacetic Acid Formula
The formula of chloroacetic acid is CH₂ClCOOH. It consists of two carbon atoms, three hydrogen atoms, one chlorine atom, and two oxygen atoms. The chlorine atom is bonded to one of the carbon atoms, while the other carbon atom is bonded to the carboxylic acid group (-COOH).
Chloroacetic Acid Molar Mass
The molar mass of monochloroacetic acid is calculated by adding up the atomic masses of its constituent elements. Monochloroacetic acid has a molar mass of approximately 94.5 grams per mole. It is determined by considering the atomic masses of carbon (C), hydrogen (H), chlorine (Cl), and oxygen (O) present in the compound.
Chloroacetic Acid Boiling Point
Monochloroacetic acid has a boiling point of around 189 degrees Celsius. At this temperature, the liquid monochloroacetic acid changes into a gas phase. The boiling point of monochloroacetic acid is influenced by intermolecular forces between its molecules and the atmospheric pressure.
Chloroacetic Acid Melting Point
The melting point of monochloroacetic acid is approximately 62 degrees Celsius. This is the temperature at which the solid form of monochloroacetic acid transitions into a liquid state. The melting point can vary slightly depending on the purity of the sample and the conditions under which it is measured.
Chloroacetic Acid Density g/mL
The density of monochloroacetic acid is approximately 1.58 grams per milliliter. It indicates the mass of monochloroacetic acid per unit volume. The density of monochloroacetic acid is influenced by factors such as temperature and pressure.
Chloroacetic Acid Molecular Weight
The molecular weight of monochloroacetic acid is approximately 94.5 grams per mole. It represents the sum of the atomic weights of all the atoms in a molecule of monochloroacetic acid. The molecular weight is useful in various calculations involving the compound, such as determining molar concentrations or quantities.
Chloroacetic Acid Structure
Monochloroacetic acid has a structure consisting of a central carbon atom bonded to a chlorine atom, a carboxylic acid group (-COOH), and two hydrogen atoms. The chlorine atom is directly attached to the carbon atom. The structural arrangement of monochloroacetic acid influences its chemical properties and reactivity.
Chloroacetic Acid Solubility
Monochloroacetic acid is moderately soluble in water. It forms hydrogen bonds with water molecules, allowing it to dissolve to some extent. The solubility of monochloroacetic acid is influenced by factors such as temperature, pH, and the presence of other substances in the solution.
| Appearance | Colorless liquid |
| Specific Gravity | 1.58 g/mL |
| Color | Colorless |
| Odor | Vinegar-like |
| Molar Mass | 94.5 g/mol |
| Density | 1.58 g/mL |
| Melting Point | 62 °C |
| Boiling Point | 189 °C |
| Flash Point | 111 °C |
| Water Solubility | Miscible |
| Solubility | Soluble in ethanol, ether, chloroform |
| Vapour Pressure | 0.23 mmHg at 25 °C |
| Vapour Density | 3.3 (air = 1) |
| pKa | 2.87 |
| pH | 1.5 – 2.5 |
Chloroacetic Acid Safety and Hazards
Monochloroacetic acid poses several safety hazards and should be handled with caution. It is corrosive to skin, eyes, and respiratory system, causing burns and irritation. Direct contact can result in severe skin and eye damage. Inhalation of its vapors or mists can irritate the respiratory tract. It is also harmful if swallowed, leading to gastrointestinal distress. Proper personal protective equipment, such as gloves and goggles, should be worn when working with monochloroacetic acid. Adequate ventilation is crucial to minimize exposure. In case of skin or eye contact, immediate rinsing with water is essential, and medical attention should be sought.
| Hazard Symbols | Corrosive, Toxic |
| Safety Description | Avoid contact. Use personal protective equipment. Ensure proper ventilation. Handle with care. |
| UN IDs | UN 1751 |
| HS Code | 2915.12.00 |
| Hazard Class | 8 (Corrosive) |
| Packing Group | II |
| Toxicity | Toxic by ingestion, inhalation, and skin absorption. Causes severe burns and eye damage. Harmful if swallowed. |
Chloroacetic Acid Synthesis Methods
Various methods enable the synthesis of monochloroacetic acid.
One commonly used method to synthesize monochloroacetic acid involves treating acetic acid with a halogenating agent, typically chlorine gas (Cl₂), in the presence of a catalyst such as sulfuric acid (H₂SO₄). The reaction between acetic acid and chlorine results in the substitution of one hydrogen atom in the acetic acid molecule with a chlorine atom, thereby forming monochloroacetic acid.
Another method entails the reaction between acetyl chloride (CH₃COCl) and water (H₂O). Water hydrolyzes acetyl chloride, leading to the formation of monochloroacetic acid. This reaction is exothermic and necessitates caution during its execution.
Monochloroacetic acid formation occurs through the carboxylation of chloromethane (CH₃Cl) by utilizing carbon dioxide (CO₂) in the presence of a robust base like sodium hydroxide (NaOH). The reaction proceeds through nucleophilic substitution, where the carboxylate group (-COOH) of the carbon dioxide molecule replaces the chloride ion.
Remember that proper handling and safety precautions are crucial for these synthesis methods due to the corrosive and toxic nature of monochloroacetic acid. Ensure careful control of reaction conditions and appropriate disposal of byproducts and waste to guarantee safe and efficient synthesis processes.
Chloroacetic Acid Uses
Monochloroacetic acid finds applications in various industries due to its versatile properties. Here are some common uses:
- Production of Herbicides: Monochloroacetic acid is a vital ingredient in the synthesis of herbicides, such as glyphosate. It aids in inhibiting the growth of unwanted plants and weeds in agriculture.
- Manufacturing of Pharmaceuticals: It serves as a building block in the production of pharmaceutical compounds, including antibiotics, antiseptics, and analgesics. Monochloroacetic acid helps modify and enhance the desired properties of these drugs.
- Dye and Pigment Industry: Manufacturers utilize monochloroacetic acid in the production of dyes and pigments. It helps in the synthesis of colorants used in textiles, paints, inks, and other decorative applications.
- Chemical Intermediates: It acts as key intermediate compound in the production of various chemicals. The synthesis of polymers, solvents, plasticizers, and other organic compounds involves the utilization of these intermediates.
- Manufacturing of Surfactants: Monochloroacetic acid plays a role in the production of surfactants, which are essential components in detergents, cleaning agents, and personal care products. Surfactants aid in reducing the surface tension between liquids, allowing better mixing and dispersing capabilities.
- Research and Laboratory Applications: Research laboratories employ monochloroacetic acid as a reagent for chemical reactions, particularly in organic synthesis and analytical procedures.
- Chemical Reactions and Organic Synthesis: It serves as an important reagent in various organic reactions, such as nucleophilic substitutions, esterifications, and carboxylation reactions.
- Electroplating: Monochloroacetic acid finds application in electroplating processes, where it acts as a source of chlorine for the deposition of metal coatings on surfaces.
These diverse applications highlight the significance of monochloroacetic acid across industries, contributing to the development of numerous products and chemical processes.
Questions:
Q: What is the value of Ka for a 0.15 M solution of chloroacetic acid with a pH of 1.86?
A: The Ka value for monochloroacetic acid can be calculated using the pH value, and it is approximately 1.4 x 10^-3.
Q: Is chloroacetic acid strong or weak?
A: Monochloroacetic acid is a weak acid.
Q: What does sodium 4-chlorophenolate + chloroacetic acid yield?
A: The reaction of sodium 4-chlorophenolate with monochloroacetic acid yields 4-chlorophenoxyacetic acid and sodium chloride.
Q: What is the Ka of chloroacetic acid?
A: The Ka value of monochloroacetic acid is approximately 1.4 x 10^-3.
Q: Is chloroacetic acid monoprotic?
A: Yes, monochloroacetic acid is monoprotic, meaning it can donate only one proton (H+ ion) in a chemical reaction.
Q: What is the ionization constant of chloroacetic acid?
A: The ionization constant (Ka) of monochloroacetic acid is approximately 1.4 x 10^-3.
Q: Is chloroacetic acid stronger than acetic acid?
A: Yes, monochloroacetic acid is stronger than acetic acid.
Q: Why is chloroacetic acid stronger than acetic acid?
A: The presence of the chlorine atom in monochloroacetic acid increases its electron-withdrawing capability, making it more acidic compared to acetic acid.
Q: What is the molar mass of chloroacetic acid?
A: The molar mass of monochloroacetic acid is approximately 94.5 grams per mole.