What Is Hydrobromic Acid Definition Formula Reactions and Uses in Chemistry
Dissolving diatomic molecules, hydrogen bromide in water gives us hydrobromic acid. Its molecular name (chemical formula) is HBr. There is a simple, single covalent bond between Bromine and Hydrogen atoms. As Bromine has a high electronegativity, the bond gets ionized easily. It makes HBr a very strong acid. It readily fumes when exposed to moist air. It is generally transported in a liquified compressed gas form. The HBr acid is commercially available in diluted form (48% acid+ 62% solution).
Hydrobromic Acid (Hbr acid) is also known as Hydronium Bromide, Bromane.
Atomic Structure of HBr
The chemical formula for HBr acid is HBr or BrH.
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Production of HBr Acid
The hydrobromic acid can be produced in laboratories.
When bromine, sulfur dioxide, and water react, sulphuric acid and hydrobromide gas are produced.
\[Br_{2}\] + \[SO_{2}\] + 2 \[H_{2}\]O → \[H_{2}\] \[SO_{4}\] + 2 HBr
An alternative method for producing The HBr acid in the lab is to mix dilute sulphuric acid with potassium bromide. This method is widely used for industrial production. The chemical expression is as shown below,
\[H_{2}\]\[SO_{4}\] + KBr → \[KHSO_{4}\] + HBr
Physical Properties of HBr
Chemical Properties of HBr
1. It is highly corrosive to metals and fabrics.
2. When HBr reacts with sulphuric acid, Sulphur dioxide, bromine, and water forms. The chemical equation can be written as
2HBr + \[H_{2}\]\[SO_{4}\] → \[Br_{2}\]+ \[SO_{2}\]+ \[2H_{2}\]O
3. When HBr reacts with propene, the result is the formation of 2- Bromopropane. The chemical expression is written as,
HBr+ \[C_{3}\]\[H_{6}\] → \[C_{3}\]\[H_{7}\]Br
4. It decomposes when heated and produces toxic fumes.
5. It is denser than air.
6. Its pH value is less than 2.
7. Its pKa value is less than -2
8. The HBr acid is incompatible with ozone and fluorine.
9. The HBr acid is not combustible by itself.
10. If exposed to heat for a longer time it can lead to an explosion.
11. The fumes of hydrobromic acid are oxidizing and can cause corrosion of wood, paper, oil, clothes, and metals.
12. When the HBr acid reacts with alkenes violent polymerization occurs.
13. Dilution of HBr gas in water can cause the generation of Heat.
14. When it comes in contact with metals, it releases flammable hydrogen gas.
15. The HBr acid neutralizes amines and inorganic hydroxides, that form salts. As the process generates heat, it should be avoided to carry out in small spaces.
16. Reacting with aluminium and iron, it produces toxic gases.
17. Fumes of HBr form clouds in a humid atmosphere.
18. When it reacts with nitrites and sulfites, it releases carbon dioxide. Though it is not toxic, heat and splashing of reaction can be hazardous.
19. It is utilized in creating inorganic bromides such as those of sodium, calcium and zinc.
20. Most preparation in the lab is done with an anhydrous compound of HBr which gets dissolved in water.
Uses of HBr Acid
HBr acid is widely used
As a catalyst and reagent in many organic preparations.
In many industrial processes such as dehydration, isomerization, hydration, polymerization.
Bromine based fumigants are used in sanitation and for disinfection treatments.
Bromide salts are found in medications.
In the extraction of mercury from cinnabar ore.
As a key raw material in the production of photosensitive materials, dyes, inorganic pharmaceutical products.
In the production of Bromium compounds that are further used in dyes, insecticides, plastic castings.
Also used widely in modern manufacturing and in various components in combination with other substances. Used to make medicines to fuels, plastics, semiconductors.
Fun Facts
HBr is a gas, but when it is dissolved in water, it becomes liquid.
In the past, diluted bromides were widely used as anti-epileptic and sedatives medicines.
To increase the storage life of fruits and vegetables, Hydrobromic acid(diluted) is used in post-harvest treatments of horticulture.
In the US, traces of bromide were found in food. It was the main cause of higher bromide exposure.
Different kinds of HBr ionization research on ice surfaces help in finding out about ways of ozone depletion in the Arctic atmosphere. This is one of the important factors for considering atmospheric chemistry.
Did You Know
William W. Carlin discovered the HBr Acid. He patented the process of creation of the acid on July 28th, 1977.
FAQs on Hydrobromic Acid Structure Properties and Applications
1. What is hydrobromic acid?
Hydrobromic acid is a strong acid formed when hydrogen bromide gas (HBr) dissolves in water to produce HBr(aq). It is a colorless, highly corrosive aqueous solution that completely ionizes in water:
HBr(aq) → H+(aq) + Br−(aq)
- Chemical formula (aqueous): HBr(aq)
- Type: Strong acid
- Conjugate base: Bromide ion (Br−)
2. Why is hydrobromic acid considered a strong acid?
Hydrobromic acid is considered a strong acid because it completely ionizes in water. In aqueous solution, nearly 100% of HBr molecules donate a proton to water:
HBr(aq) + H2O(l) → H3O+(aq) + Br−(aq)
- Very large acid dissociation constant (Ka)
- Strong electrolyte in aqueous solution
- Produces high concentration of H+ (or H3O+)
3. What is the chemical formula of hydrobromic acid?
The chemical formula of hydrobromic acid is HBr(aq). It consists of hydrogen and bromine atoms in a 1:1 ratio.
- Gas form: HBr(g) (hydrogen bromide)
- Aqueous form: HBr(aq) (hydrobromic acid)
- Molar mass: approximately 80.91 g/mol
4. How is hydrobromic acid prepared in the laboratory?
Hydrobromic acid is prepared in the laboratory by reacting a bromide salt with a non-oxidizing acid like phosphoric acid. A common method is:
NaBr(s) + H3PO4(aq) → HBr(g) + NaH2PO4(aq)
The hydrogen bromide gas produced is then dissolved in water to form HBr(aq).
- Phosphoric acid is preferred over sulfuric acid
- Concentrated H2SO4 can oxidize Br− to Br2
5. What is the difference between hydrogen bromide and hydrobromic acid?
Hydrogen bromide is HBr in the gaseous state, while hydrobromic acid is HBr dissolved in water.
- HBr(g): Covalent gas, called hydrogen bromide
- HBr(aq): Ionized in water, called hydrobromic acid
- Only the aqueous form shows strong acidic behavior
6. How does hydrobromic acid react with metals?
Hydrobromic acid reacts with reactive metals to produce a bromide salt and hydrogen gas. For example:
Zn(s) + 2HBr(aq) → ZnBr2(aq) + H2(g)
- Metal displaces hydrogen from the acid
- Forms metal bromide (e.g., ZnBr2)
- Hydrogen gas is released
7. How does hydrobromic acid react with bases?
Hydrobromic acid reacts with bases in a neutralization reaction to form a bromide salt and water. For example:
HBr(aq) + NaOH(aq) → NaBr(aq) + H2O(l)
- Acid provides H+
- Base provides OH−
- Products: salt (NaBr) and water
8. What are the common uses of hydrobromic acid?
Hydrobromic acid is commonly used in the production of bromide salts and in organic synthesis reactions.
- Preparation of inorganic bromides such as KBr and NaBr
- Conversion of alcohols to alkyl bromides
- Pharmaceutical and chemical manufacturing
- Catalyst in certain organic reactions
9. Is hydrobromic acid stronger than hydrochloric acid?
Hydrobromic acid is slightly stronger than hydrochloric acid in aqueous solution.
- Both are strong acids that ionize completely
- Acid strength increases down Group 17 (HCl < HBr < HI)
- Weaker H–Br bond compared to H–Cl makes proton donation easier
10. What safety precautions should be taken when handling hydrobromic acid?
Hydrobromic acid must be handled with protective equipment because it is highly corrosive and can cause severe burns.
- Wear gloves, goggles, and lab coat
- Use in a well-ventilated area or fume hood
- Avoid skin and eye contact
- Store in corrosion-resistant containers
