Ur answer is..... HBr is the formula of hydrogen Bromide.

H stand 4 Hydrogen.
Br stand 4 Bromide.

Formula of Hydrogen Bromide (HBr)

Hydrogen bromide, also known as hydrobromic acid, is a chemical compound composed of the elements hydrogen (H) and bromine (Br). Its chemical formula is HBr.

Structure of Hydrogen Bromide

Hydrogen bromide exists as a diatomic molecule, meaning it consists of two atoms (one hydrogen and one bromine) bonded together. The hydrogen atom forms a single covalent bond with the bromine atom, resulting in a linear molecular structure.

Physical Properties of Hydrogen Bromide
- Hydrogen bromide is a colorless gas at room temperature and pressure.
- It has a sharp, pungent odor.
- The gas is highly soluble in water, forming hydrobromic acid.
- Hydrogen bromide has a boiling point of -66.8°C and a melting point of -86.9°C.

Chemical Properties of Hydrogen Bromide
- Hydrogen bromide is highly acidic in nature and a strong acid.
- It readily dissociates in water to form hydrobromic acid, which is a strong acid as well.
- HBr can react with various metals, such as zinc or magnesium, to form metal bromides and release hydrogen gas.
- It can also react with bases to form bromide salts and water.
- Hydrogen bromide can undergo various chemical reactions, including addition reactions, substitution reactions, and oxidation-reduction reactions, due to the presence of the highly reactive bromine atom.

Uses of Hydrogen Bromide
- Hydrogen bromide is commonly used in organic synthesis as a catalyst or reagent.
- It is used in the production of pharmaceuticals, dyes, and perfumes.
- Hydrobromic acid, derived from hydrogen bromide, is used in the synthesis of inorganic bromides and as a laboratory reagent.

Preparation of Hydrogen Bromide
Hydrogen bromide can be prepared by the reaction of an alkali metal bromide with concentrated sulfuric acid. The reaction can be represented by the following equation:

2NaBr + H2SO4 → Na2SO4 + 2HBr

In this reaction, sodium bromide (NaBr) reacts with sulfuric acid (H2SO4) to produce sodium sulfate (Na2SO4) and hydrogen bromide (HBr) gas.

In summary, the formula of hydrogen bromide is HBr. It is a diatomic molecule consisting of one hydrogen atom and one bromine atom. Hydrogen bromide is a colorless gas with a pungent odor and is highly acidic. It is used in various chemical reactions, organic synthesis, and the production of pharmaceuticals. The compound can be prepared by the reaction of an alkali metal bromide with concentrated sulfuric acid.