Hypobromous Acid Formula: Structure, Properties, Uses

The Hypobromous Acid Formula is a representation of a relatively weak and unstable acid that shares chemical and physical properties with hypohalites. Hypohalites are oxyanions containing a halogen in the +1 oxidation state. Hypobromous acid, in contrast, possesses the ability to combat germs and bacteria, making it valuable as a versatile disinfectant, oxidizer, bleach, and deodorizer.

The chemical formula for the hypobromite ion is (BrO), with bromine having an oxidation state of +1. Hypobromite is a bromine compound akin to hypochlorites, which are present in common bleaches and immune cells. In certain respects, hypobromite resembles hypochlorite and can also be employed as a germ-killing agent and an antiparasitic substance.

Hypobromous Acid Formula

Hypobromous acid, with the chemical formula HOBr, is a relatively fragile and unstable acid primarily found in aqueous solutions. It is produced through both biological processes and commercial means for use as a disinfectant. Solid salts of hypobromite are infrequently isolated.

Hypobromous Acid Formula Structure

Hypobromous acid (HBrO) has the following structural features:

Hypobromous Acid Formula Lewis Structure

The Lewis structure of hypobromous acid (HBrO) can be represented as follows:

In this structure, there is a single covalent bond between hydrogen (H) and bromine (Br), and another covalent bond between bromine (Br) and oxygen (O). Bromine and oxygen each have unshared pairs of electrons (lone pairs) in this molecule.

Hypobromous Acid Hydrogen Bonding

HBrO can engage in hydrogen bonding as it contains hydrogen atoms bonded to electronegative atoms like O and Br, wherein hydrogen bonding happens when a highly electronegative atom, such as O, N, or F, attracts the hydrogen bonded to it towards another nearby electronegative atom.

In HBrO, the hydrogen atom (H) is bonded to oxygen (O), and the oxygen atom has a lone pair of electrons. This lone pair on the oxygen atom can act as a hydrogen bond acceptor, and the hydrogen atom can act as a hydrogen bond donor. This allows HBrO to form hydrogen bonds with other molecules or ions that have hydrogen bond-donating and accepting sites.

Hydrogen bonding in HBrO can influence its properties and interactions with other substances, particularly in aqueous solutions or when it interacts with other compounds that can form hydrogen bonds.

Hypobromous Acid Formula Reaction

The formula for Hypobromous Acid is HBrO, representing the chemical compound formed when bromine reacts with water:

Br₂ + H2O → HBrO

The reaction between bromine and water is in equilibrium, forming both hypobromous acid (HOBr) and hydrobromic acid (HBr):

Br₂ + H2O ⇄ HOBr + HBr

Hypobromous Acid Formula Properties

Physical Properties of Hypobromous Acid

• Hypobromous acid has a molecular weight of 96.911 g/mol.
• Its density is 2.470 g/cm.
• It has a pKa of 8.65, indicating its level of acidity.
• The boiling point of hypobromous acid falls within the range of 20 to 25°C.

Chemical Properties of Hypobromous Acid

In nature, hypobromous acid is produced by bromoperoxidase, enzymes that catalyse the oxidation of bromide with hydrogen peroxide:

Br^– + H₂O₂ ⇄ HOBr + OH^–

With a pKa around 8.65, hypobromous acid only partially dissociates in water at a pH of 7. The hypobromite salts, like the acid, are unstable and undergo a complex disproportionation reaction to produce bromate and bromide salts:

3BrO ⁻ (aq) → 2Br ⁻ (aq) + BrO − 3(aq)

Hypobromous Acid (HOBr) Uses

• HOBr is a versatile compound known for its ability to effectively eliminate and deactivate many microorganisms, making it useful as a bleach, oxidant, deodorant, and disinfectant.
• HOBr is naturally produced by warm-blooded vertebrate organisms, especially eosinophils, a type of white blood cell.
• Eosinophil peroxidase, an enzyme that primarily utilizes bromide, contributes to the formation of HOBr in eosinophils.
• HOBr is used as a germicidal agent in hot tubs and spas, where an oxidizing agent is used to generate hypobromite in a manner similar to how eosinophils utilize peroxidase.
• HOBr is particularly effective when used in conjunction with its chemical relative, hypochlorous acid.

Hypobromous acid (HOBr) serves as a multifunctional compound with a range of valuable applications. Its efficacy as a bleach, oxidant, deodorant, and disinfectant is attributed to its ability to eliminate and deactivate various microorganisms. Notably, HOBr is naturally produced by warm-blooded vertebrate organisms, primarily by eosinophils, and its formation is catalysed by eosinophil peroxidase. 

Furthermore, HOBr is utilised as a germicidal agent in environments such as hot tubs and spas, where an oxidising agent generates hypobromite, akin to its formation in eosinophils. When combined with hypochlorous acid, HOBr iseffectiveness is further enhanced, making it a valuable chemical in various practical applications.