Chloroacetic Acid

Introduction

Chloroacetic acid was first prepared by French chemist Felix LeBlanc in 1843. He made it possible in the presence of sunlight, simply by chlorinating Acetic acid. In the year 1857, A German Chemist named Reinhold Hoffmann prepared Chloroacetic acid in the presence of Chlorine and sunlight by refluxing glacial Acetic acid. In the same year, French chemist Charles Adolphe Wurtz made the Chloroacetic acid by hydrolysis of Chloroacetyl Chloride.

What is Chloroacetic acid?

Chloroacetic acid is a chemical name, which can be defined as an organochlorine compound. It can be represented as the $\mathrm{C_{2}H_{3}O_{2}Cl}$. It is also referred to as the monochloroacetic acid or MCA. It can increase the acidity of the acetic acid simply by dispersing the negative charge by inductive effect and it can work by stabilizing the acetate anion. In simple words, it can be derived from Acetic acid. $\mathrm{C_{2}H_{3}O_{2}Cl}$ functions both as the herbicide and alkylating agent.

Structure of Chloroacetic acid

Figure 1 − Structure of Chloroacetic Acid

$\mathrm{C_{2}H_{3}O_{2}Cl}$ is also called the 2-Chloroacetic acid or Chloroethanoic acid. A Chlorocarboxylic acid carries a 2-Chloro substituent and by nature $\mathrm{C_{2}H_{3}O_{2}Cl}$ is colorless or it can be lightbrown crystalline solid. It shows two types of nature in the water. It can be dissolved in water and even can sink. If it is melted into liquid form, it can cause thermal burns. Moreover, if it comes in the contact with skin or ingested, inhaled or absorbed, it can show its toxic nature. Other than that, $\mathrm{C_{2}H_{3}O_{2}Cl}$ is combustible and corrosive.

Properties of Chloroacetic acid

The chemical formula of Chloroacetic acid is $\mathrm{C_{2}H_{3}O_{2}Cl}$. The molecular weight of the Chloroacetic Acid is 94.49 g/mol. The density of $\mathrm{C_{2}H_{3}O_{2}Cl}$ is 1.58 g/cm3. Boiling point and melting point of Chloroacetic acid are 189.3°C and 63°C respectively. The crystals of $\mathrm{C_{2}H_{3}O_{2}Cl}$ are hygroscopic by nature. It may be colorless but has a pungent odor that is similarly strong as the vinegar. From it many hazardous decomposition products can form, under the condition of the fire. The decomposition can provide a rise to Hydrogen Chloride gas and the Carbon Oxides.

Preparation of Chloroacetic acid

Figure 2 − Hydrolysis of Chloroacetic acid

Hydrolysis of chloroacetic acid, Creative Commons Attribution-Share Alike 4.0, via Wikimedia Common

For industrial use, Chloroacetic acid can be prepared using two major methods. Globally, if measured, per year at least 4,20,000 tons of Chloroacetic acid is prepared. They are the predominant method and entails hydrolysis of Trichloroethylene.

The first method means the predominant method, which is used vividly for producing Chloroacetic acid. This process involves chlorination of the acetic acid where the acetic anhydride behaves as the catalyst. The chemical reaction can be represented as −

$$\mathrm{H_{3}C\:-\:COOH\:+\:Cl_{2}\:\rightarrow\:ClH_{2}C\:-\:COOH\:+\:HCl}$$

The one major drawback of this method is that it produces two impurities such as Dichloroacetic acid and Trichloroacetic acid.

The second method entails hydrolysis of Trichloroethylene. In this method, hydrolysis is performed at 130-140°C in a concentrated solution of Sulphuric acid, where it is concentrated at least 75%. The equation that can represent the chemical reaction is −

$$\mathrm{ClHC\:=\:CCl_{2}\:+\:2H_{2}O\:\rightarrow\:ClH_{2}C\:-\:COOH\:+\:HCl}$$

The result of this process is considered highly pure as a product, which is the basic difference between this method with the predominant method.

Use of Chloroacetic acid

Chloroacetic acid can be used in many sectors. It is used as the intermediate in the production of Ethyle Chloroacetate. It is also used vividly as a bacteriostat and as herbicide. It can be used as the preservative and chemical intermediate. It is considered a crucial component in the field of the production of pesticides and drugs and dyes. It is most importantly used to prepare thickening agent Carboxymethyl Cellulose and cCrboxymethyl Starch. Chloroacetic acid is one of the most essential components in organic chemistry.

Important Facts about Chloroacetic Acid

Health hazards

As Chloroacetic acid is toxic by nature, it can work as lethal for the human body with a dose of 50-500 mg/kg. If it comes in contact with skin it can cause irritation and burning sensation. Even it can lead to depression and respiratory system depression.

Safety measures

• The most important thing about Chloroacetic acid is that it is combustible.

• With the help of it, thermal burn can happen.

• It shows its toxic nature when corrosive to tissues and metals.

Conclusion

Chloroacetic acid is a very crucial element in the field of organic chemistry and is also referred to as the MCA. This is Carboxylic acid, and is considered useful for building the block in organic synthesis. Compounds that are related to Chloroacetic acid are Dichloroacetic acid and Trichloroacetic acid.

FAQs

1. What is the main use of Chloroacetic acid?

Chloroacetic acid is a sand-like material, which is mainly used to fulfill the purpose of making dye, chemicals, herbicides, and even a disinfectant.

2. What is the basic nature of Chloroacetic acid?

Chloroacetic acid is considered the strongest acid. It is more acidic than acetic acid.

3. How Chloroacetic acid can be made?

Chloroacetic acid can be made using different methods. However, the most common way in which Chloroacetic acid can be prepared is by chlorinating Acetic acid in the presence of the catalytically effective amount of Acetic anhydride, Acetyl Chloride.

4. What is the most harmful acid?

Hydrofluoric acid is considered the most dangerous and harmful acid on the list. It does not even dissociate completely in the water.

5. What is the strongest acid?

The strongest acid in this world is Carborane acid, it is even strongest than Sulphuric acid. The Carborane acid is a super acid that can be contained in a container.