Benzoic Acid

Benzoic Acid is a white, solid organic compound that belongs to the family of carboxylic acid. The chemical formula of Benzoic Acid is C₆H₅COOH. It is used in the manufacturing of certain products including perfumes, toothpaste, face wash, chemicals, dyes, insect repellent, and the list is endless. It is majorly used as a preservative for certain food items like pickles, jam, etc.

In this article, we will discuss more about Benzoic Acid, its structure, properties, and its uses.

What is Benzoic Acid?

Benzoic acid is an organic compound with Chemical formula C₆H₅COOH or C₇H₆O₂. It is a white or colorless crystal that belongs to the family of carboxylic acids. It is used in various industries and is widely used as a preservative. It has a pleasant fruity smell. Sodium Benzoate, a salt used in food preservation is also a derivative of Benzoic acid.

History of Benzoic Acid

Benzoic acid was first discovered in the 16th century. It was first extracted naturally from benzoin resin and hence the name is benzoic acid. Benzoin resin was earlier used in traditional medicines. A German chemist Adolf von Baeyer was the first to synthesize benzoic acid in 1875. It was extracted from a compound named toluene which was derived from coal tar. Nowadays, benzoic acid is mainly synthesized in laboratories.

Benzoic Acid Structure

Benzoic acid consists of a Benzene (hexagonal) ring of six carbons. Each carbon in the benzene ring has an alternate single and double bond. Further, 5 out of 6 carbons are single-bonded with hydrogen atoms. Apart from this, the ring is also attached to a carboxyl functional group (-COOH) which gives acidic properties to the benzoic acid. The carboxyl group consists of a carbon which is double-bonded with an oxygen atom and single-bonded to a hydroxyl group.

Benzoic Acid Formula

Benzoic Acid Structurcal Formula is C₆H₅COOH or C₇H₆O₂. The molecule of benzoic acid consists of seven carbon atoms, six hydrogen atoms, and two oxygen atoms.

Preparation of Benzoic Acid

Benzoic acid can be prepared in various ways, a few of them are:

Industrial Preparation: Benzoic acid can be produced in industries by partial oxidation of toluene. In this process, Cobalt or manganese naphthenates act as a catalyst.

C₆H₅CH₃ + O₂ → C₆H₅COOH – H₂O

Hydrolysis: Benzoic acid can be formed by the process of hydrolysis of Benzamide or Benzonitrile with a strong base like sodium hydroxide.

Oxidation: Benzoic acid can be formed from Benzyl alcohol or Benzyldehyde by the process of oxidation in the presence of an oxidizing agent like potassium permanganate.

Properties of Benzoic Acid

Benzoic acids have many properties which make them versatile and useful in many industries. Its properties make it unique and contribute to a wide range of uses and applications of benzoic acids. The physical and chemical properties of benzoic acid are described below.

Physical Properties of Benzoic Acid

Physcial Properties of the Benzoic Acisd are added below as,

• State: Benzoic acid is a white or colourless crystalline solid.
• Solubility: Benzoic acid is slightly soluble in water, but it is highly soluble in organic solvents like ethanol.
• Density: Benzoic acid has a density of around 1.27 grams per cubic centimeter.
• Odor: Benzoic acid generally has a pleasant, fruity smell.
• Molecular weight: The molecular weight of benzoic acid is 122.12 g/mol.

Melting Point of Benzoic Acid

The melting point of Benzoic acid is about 122° Celsius.

Boiling Point of Benzoic Acid

The boiling point of Benzoic acid is about 249° Celsius.

Benzoic Acid pKa

The pKa value of Benzoic Acid is 4.19 and hence it is a week acid.

Benzoic Acid Density

The density of Benzoic Acid is 1.27 g/cm³

Benzoic Acid Solubility

Benzoic acid is a monobasic aromatic acid, that is soluble in alcohol, ether, and benzene, but poorly soluble in water.

Benzoic Acid to Aniline

Benzoic Acid can be easily converted to Anline by the reaction added below as,

C₆H₅COOH + PCl₅ (Catalyst) → C₆H₅COCl + NH3 → C₆H₅CONH₂ + HCl

Now using the Hoffman Bromamide Degradation Aniline is produced.

C₆H₅CONH₂ + Br₂/NaOH → C₆H₅NH₂

Chemical Properties of Benzoic Acid

Chemical Properties of the Benzoic Acisd are added below as,

• Stability: Benzoic acid is highly stable under normal circumstances and it does not decompose easily.
• Acidity: It is a weak acid and thus it can donate a hydrogen ion (H+) to form benzoate ions.
• pH: Being a weak acidic it has a pH value of around 2.8
• Antimicrobial Properties: Benzoic acid has antimicrobial properties therefore its salts are commonly used as preservatives in food and cosmetics.
• Sublimation: Benzoic acid can undergo sublimation i.e. it can change from a solid directly into a vapor without changing into a liquid.
• Reactivity: It can undergo various chemical reactions, such as nitration, oxidation, decarboxylation, etc.

Uses of Benzoic Acid

Various uses of the Benzoic Acid are,

• Food Preservative: Benzoic acid is commonly used as a preservative in food and beverages.
• Flavoring Agent: Benzoic acid is not only used as a preservative for various food items but it is also used as a flavoring agent in various food and beverage products. It gives a tangy or slightly sweet taste.
• Personal Care Products: Benzoic acid is used as a preservative and fragrance ingredient in various cosmetics, perfumes, and hair care products.
• Industrial Applications: Benzoic acid is used in the production of various products like dyes, plastics, chemicals, herbicides, and synthetic fibers.
• Pharmaceutical applications: Benzoic acid is used in the production of various medications, such as cough syrups. It is also found in antiseptic ointments and creams.

Read More,

• Acid, Base and Salt
• Ethanol
• Structure of Benzene
• Aromatic Compounds

FAQs on Benzoic Acid

1. What is Chemical Formula of Benzoic Acid?

Benzoic acid is an organic compound with Chemical formula C₆H₅COOH or C₇H₆O₂.

2. What is Benzoic Acid?

Benzoic Acid is a white, solid organic compound that belongs to the family of carboxylic acid. It is used in the manufacture of certain products including perfumes, toothpaste, face wash, chemicals, dyes, insect repellent, and the list is endless. It is majorly used as a preservative for certain food items and beverages like pickles, jam, etc.

3. What are the Uses of Benzoic Acid?

The uses of benzoic acid is endless, however it is majorly used as a preservative in various food items, beverages, cosmetic items, etc. It is also used as an insect repellent and in manufacturing of various products like toothpaste, facewash, herbicides, medicines, chemicals, perfumes, etc.

4. Is Benzoic Acid Soluble in Water?

Benzoic acid is slightly soluble in water, but it is highly soluble in organic solvents like ethanol. However, the solubility of Benzoic acid in water is directly proportional to the temperature i.e it increases with the increase in temperature. At 0°C, the solubility of benzoic acid in water is 1.7 grams per litre and at 100 °C, its solubility in water increases to 56.31 grams per litre.

5. What is IUPAC Name of Benzoic Acid?

The IUPAC name of Benzoic Acid is Benzenecarboxylic acid.

6. Which Acid is Stronger Benzoic Acid or Acrylic Acid?

Benzoic acid is stronger than Acrylic acid because the double bond in benzoic acid is more electron donating making it a stronger acid than acrylic acid.

7. Is Benzoic Acid Carboxylic Acid?

Yes, benzoic Acid is a Carboxylic Acid. Benzoic acid is a benzene ring attached to a carboxylic acid (-COOH).

8. How to Change Benzoic Acid to Benzaldehyde?

The conversion of Benzoic acid to Benzaldehyde is done in two steps:

• Step 1: First, benzoic acid is converted to benzoyl chloride by the process of chlorinization.
• Step 2: Then, the formed benzoyl chloride is reduced to Benzaldehyde by Rosenmund’s reduction.

9. How is Benzoic Acid Prepared?

Benzoic acid can be produced in industries by partial oxidation of toulene. In this process, Cobalt or manganese naphthenates act as a catalyst.