The key difference between hydrogen bromide and hydrobromic acid is that hydrogen bromide is a molecule having a hydrogen atom bonded to a bromine atom through a covalent chemical bond whereas hydrobromic acid is a strong acid formed from the dissolution of hydrogen bromide in water.
Hydrogen bromide is a simple inorganic compound. It contains a hydrogen atom having a single covalent bond with a bromine atom. When this substance is dissolved in water, it forms hydrobromic acid.
CONTENTS
1. Overview and Key Difference
2. What is Hydrogen Bromide
3. What is Hydrobromic Acid
4. Side by Side Comparison – Hydrogen Bromide vs Hydrobromic Acid in Tabular Form
5. Summary
What is Hydrogen Bromide?
Hydrogen bromide is an inorganic compound having the chemical formula HBr. It is a diatomic molecular compound, and we can categorize it as a hydrogen halide. In its pure form, hydrogen bromide is a colourless gas and has an acrid odour. Moreover, HBr is soluble in water, alcohol, and some other organic solvents.
Figure 01: Structure of Hydrogen Bromide Molecule
This substance is highly water-soluble. It can form hydrobromic acid when dissolved in water and saturated to about 68.85%. Both the anhydrous form and the aqueous form of hydrogen bromide are important reagents in the preparation of bromide compounds.
Hydrogen bromide is important in producing inorganic and organic bromine compounds. Moreover, free radical addition of HBr to alkenes give alkyl bromides. These alkylating agents are important precursors for fatty amine derivatives.
We can prepare hydrogen bromide industrially via combining hydrogen and bromine at temperatures between 200 and 400 Celsius degrees temperature. Typically, this reaction is catalyzed by platinum or asbestos. Apart from that, the laboratory synthesis of hydrogen bromide is done mainly by the distillation of a solution of sodium bromide or potassium bromide with phosphoric acid or sulfuric acid.
When considering the safety regarding hydrogen bromide, it is highly corrosive and irritating to inhalation; thus, we should carefully handle this substance.
What is Hydrobromic Acid?
Hydrobromic acid is a strong acid prepared by dissolving hydrogen bromide in water. It is a stronger acid than hydrochloric acid but less acidic than hydroiodic acid. However, this is one of the strongest known mineral acids. This acid appears as a colourless/faint yellow liquid, and it has an acrid odour.
Figure 02: Appearance of Hydrobromic Acid
Hydrobromic acid has many uses, including the use of this acid in the production of inorganic bromides, especially the bromides of zinc, calcium, and sodium. Furthermore, it is a useful reagent in generating organobromine compounds. Hydrobromic acid can catalyze alkylation reactions and the extraction of certain ores.
When considering the synthesis of hydrobromic acid, it can be prepared in the laboratory via the reaction between Br2, SO2, and water. This reaction gives hydrobromic acid and sulfuric acid as the byproduct. However, the typical laboratory production method is the production of anhydrous HBr, which is then dissolved in water.
What is the Difference Between Hydrogen Bromide and Hydrobromic Acid?
Hydrobromic acid is the aqueous form of hydrogen bromide substance. The key difference between hydrogen bromide and hydrobromic acid is that hydrogen bromide is a molecule having a hydrogen atom bonded to a bromine atom through a covalent chemical bond whereas hydrobromic acid is a strong acid formed from the dissolution of hydrogen bromide in water.
Below infographic tables more differences between hydrogen bromide and hydrobromic acid.
Summary – Hydrogen Bromide vs Hydrobromic Acid
Hydrobromic acid is the aqueous form of hydrogen bromide substance. The key difference between hydrogen bromide and hydrobromic acid is that hydrogen bromide is a molecule having a hydrogen atom bonded to a bromine atom through a covalent chemical bond whereas hydrobromic acid is a strong acid formed from the dissolution of hydrogen bromide in water.
Reference:
1. “Hydrogen Bromide”. Science Direct, Available here.
Image Courtesy:
1. “Hydrogen-bromide-2D-dimensions” By KES47 – (Public Domain) via Commons Wikimedia
2. “Hydrobromic acid” By MDaxo – Own work (CC BY-SA 4.0) via Commons Wikimedia