Benzoic Acid Properties(23 Facts You Should Know)

Benzoic acid is an organic compound. Let us study some facts about benzoic acid.

Benzoic acid is a crystalline white solid, which is the simplest aromatic acid. Benzoic acid is used in a number of industries mainly due to its property of providing preservation for the long term. It is obtained from a variety of natural sources and also acts as an intermediate in reactions that include biosynthesis.

Let us discuss below some more details about Benzoic acids, such as IUPAC name, color, density, and reaction with metals.

Benzoic Acid IUPAC Name

The IUPAC(International Union of Pure and Applied Chemistry) of benzoic acid is Benzoic acid or Benzenecarboxylic acid.

Benzoic Acid Chemical Formula

Benzoic acid has the chemical formula of C₆H₅COOH while the empirical formula of benzoic acid is C₇H₆O₂. The benzoic acid formula contains seven carbon atoms, 6 hydrogen atoms, and two oxygen atoms.

Benzoic Acid CAS Number

The CAS number(authentic numeric identifier which can contain upto10 digits) of benzoic acid is 65-85-0.

Benzoic Acid Chemspider ID

The ChemSpider ID(ChemSpider is a free chemical structure database) for benzoic acid is 238.

Benzoic Acid Chemical Classification

Benzoic acid is chemically classified as the simplest aromatic carboxylic acid. The benzene ring of the benzoic acid is linked with the carbon of carboxyl group.

Benzoic Acid Molar Mass

The molar mass(mass of one mole of a substance) of benzoic acid is 122.123 g/mol.

Benzoic Acid Color

Benzoic acid is colorless or white solid.

Benzoic Acid Viscosity

The viscosity of benzoic acid is 1.26 mPa (130^oC).

Benzoic Acid Molar Density

The molar density of benzoic acid is 0.0088 mol/cm³, and the density of benzoic acid is 1.0749 g/cm³.

Benzoic Acid Melting Point

The melting point of benzoic acid is 122 °C (395 K) or 252 o F.

Benzoic Acid Boiling Point

The boiling point of benzoic acid is 250 °C (523 K) or 482 °F.

Benzoic Acid State at Room Temperature

At room temperature, benzoic acid appears as a fine thread-like crystalline solid. It is insoluble in water and slightly soluble in cold water but is easily soluble in organic solvents.

Benzoic Acid Covalent Bond

The benzene ring in the benzoic acid molecule consists of alternate single and double covalent bonds between the carbon atoms of the rings, the carbon of the carboxyl group forms a covalent bond with one of the carbons of the benzene ring, one with the oxygen and one with the hydroxyl group oxygen atom.

Benzoic Acid Covalent Radius

The covalent radius of benzoic acid cannot be determined as the covalent radius can only be calculated for any single atom.

Benzoic Acid Electron Configurations

Electronic configurations show how the distribution of electrons in the orbitals of an atom takes place. Let us discuss the electronic configuration of benzoic acid in detail. 
The electronic configuration of carbon is written as [He] 2s² 2p². For oxygen, the electronic configuration is written as [He] 2s² 2p⁴. The electronic configuration of Hydrogen is 1s¹.

Benzoic Acid Oxidation State

The oxidation state of all the carbons in benzoic acid is +3. The oxygen of the carboxyl group has a -2 charge, and the hydroxyl hydrogen has +1 an oxidation state.

Benzoic Acid Acidity/Alkaline

Benzoic acid is a weak organic acid with a pK_a value of 4.19. The sodium salt of benzoic acid, known as sodium benzoate is highly soluble in water.

Is Benzoic Acid Odourless?

Benzoic acid has a pleasant faint odor.

Benzoic Acid Crystal structure

Benzoic acid has a monoclinic crystal structure and planar molecular shape. The space group of Benzoic acid is P21/n with lattice parameters as a = 7.101A^o, b = 25.48A^o, and c= 7.730A^o.

Benzoic Acid Polarity and Conductivity

Benzoic acid consists of a polar carboxylic group that contains two electronegative oxygen atoms, but the bulk amount of Benzoic acid is nonpolar. It is insoluble in water but is soluble in organic solvents. Benzoic acid is not a good conductor due to the low degree of dissociation in the molten state.

Benzoic Acid Reaction With Acid

Benzoic acid reacts with acids and produces a number of products and water. It reacts with fuming sulfuric acid and undergoes a sulfonation reaction. In this reaction, the hydrogen atom present on the ring carbon, which is meta to the carboxylic group, is replaced by the SO₃H functional group.

C₆H₅COOH + H₂SO₄ = m-SO₃H-C₆H₅COOH

Benzoic Acid Reaction With Base

Benzoic acid consists of a carboxylic group that reacts with a base and produces a salt. When benzoic acid reacts with sodium hydroxide, sodium benzoate is formed. When sodium benzoate reacts with an acid, it gives the reactant back again. Benzoic acid is toxic, but sodium benzoate is very less toxic.

C₆H₅COOH + NaOH =C₆H₅COO^–Na⁺ 

Benzoic Acid Reaction With Oxide

When benzoic acid reacts with oxides, a reduction reaction takes place, which produces a benzene ring. For example, when benzoic acid is reacted with calcium oxide, the acid is reduced to a benzene ring and produces calcium carbonate as the side product of the reaction.

C₆H₅COOH + CaO + Heat = C₆H₆ + CaCO₃

Conclusion

Benzoic acid was formerly known as gum benzoin. It is mainly used in the production of phenol and in curing many skin-related ailments. Benzoic acid mainly gives an electrophilic substitution reaction as it contains an electron-withdrawing carboxylic group. Benzoic acid is meta-directing.