Bromic Acid (HBrO3): Properties, Risks And Uses

The bromic acid, also known as bromate or hydrogen bromic acid (V), is a chemical compound of formula HBrO3. 
It is a bromine oxacid with a structure analogous to chloric acid (EMBL-EBI, 2014). The compound is a very strong acid. Its structure is presented in figure 1 (EMBL-EBI, 2008).

To prepare bromic acid, a soluble bromate is usually dissolved in water and a soluble barium salt is added. Poorly soluble barium bromate precipitates.

Bromic acid structure formula.

Figure 1: structure of bromic acid.

The barium bromate can then be dissolved in water and acidified with sulfuric acid to precipitate the basically insoluble barium sulfate and leave the bromic acid behind (see image above):

2KBrO3 (aq) + BaCl2 (aq) -> Ba (BrO3) 2 (s) + 2KCl (aq)

Ba (BrO3) 2 (aq) + H2SO4 (aq) -> 2HBrO3 + BaSO4

The compound can also be produced by the decomposition of bromine pentachloride in alkaline solution according to the reaction:

BrCl5 + 3 H2O → HBrO3 + 5 HCl

Bromic acid is a strong oxidizing agent. The bromate ion can be further oxidized with elemental fluorine or xenon difluoride in the presence of base, oxidation accompanied by small explosions and the Teflon tube caught in fire (My Favorite Chemicals, SF).

Article index

  • one

    Physical and chemical properties of bromic acid 

  • two

    Reactivity and hazards

    • 2.1

      In case of contact with the eyes

    • 2.2

      In case of skin contact

    • 23

      In case of inhalation

  • 3

    Applications

  • 4

    References

Physical and chemical properties of bromic acid

 

Bromic acid exists only in colorless solution (up to 50% w / v) that turns yellowish in contact with air (National Center for Biotechnology Information., 2017). Its appearance is shown in figure 2.

Figure 2: appearance of bromic acid.

The compound has a molecular weight of 128.91 g / mol and decomposes at 100 ° C and has a pKa of -2. Being an unstable compound, its physicochemical properties were obtained through computational calculations.

It has a melting point of 206.04 ° C, a boiling point of 517.26 ° C and a solubility in water of 1 x 106 mg / l at 25 ° C (Royal Society of Chemistry, 2015).

The compound is a strong oxidizing agent. When mixed with ethanol or ether, it decomposes to form acetic acid in an exothermic reaction. It is essential for the production of bromate salts (BrO3-) that are prepared by reacting carbonates or metal oxides with bromic acid (Watts, 1870).

Reactivity and hazards

Bromic acid is an unstable compound decomposing to elemental bromine. Being a strong acid, it is extremely dangerous in case of contact with the skin (corrosive and irritant), in contact with the eyes (irritant) and in case of ingestion. Very dangerous too, in case of inhalation.

Severe overexposure can cause lung damage, suffocation, loss of consciousness, or death. Prolonged exposure can cause skin burns and ulcerations. Inhalation overexposure may cause respiratory irritation.

Inflammation of the eye is characterized by redness, watering, and itching. Inflammation of the skin is characterized by itching, peeling, redness, and occasionally blistering.

The substance is toxic to the kidneys, lungs and mucous membranes. Repeated or prolonged exposure to the substance can damage these organs.

In case of contact with the eyes

Check if contact lenses are being worn and remove them immediately. Eyes should be flushed with running water for at least 15 minutes, keeping the eyelids open. Cold water can be used. Eye ointment should not be used.

In case of skin contact

If the chemical comes into contact with clothing, remove it as quickly as possible, protecting your own hands and body. Place the victim under a safety shower.

If the chemical accumulates on the exposed skin of the victim, such as hands, the contaminated skin is gently and carefully washed with running water and non-abrasive soap. Cold water can be used. If irritation persists, seek medical attention. Wash the contaminated clothing before using it again.

If the contact with the skin is severe, it should be washed with a disinfectant soap and cover the contaminated skin with an antibacterial cream.

In case of inhalation

It is advisable to let the victim rest in a well-ventilated area. If inhalation is severe, the victim should be evacuated to a safe area as soon as possible. Loosen tight clothing such as a shirt collar, belt, or tie. If the victim finds it difficult to breathe, oxygen should be administered.

If the victim is not breathing, mouth-to-mouth resuscitation is performed. Always keeping in mind that it may be dangerous for the person providing aid to give mouth-to-mouth resuscitation when the inhaled material is toxic, infectious, or corrosive.

If swallowed, do not induce vomiting. Loosen tight clothing such as shirt collars, belts, or ties. If the victim is not breathing, perform mouth-to-mouth resuscitation.

In all cases, immediate medical attention should be sought.

Applications

Bromic acid is used as a powerful oxidizing agent in laboratory reactions. It is used to produce chemical compounds such as iodates, chloric acid, tetraihonic acid among others.

It is also used for the production of bromates such as iron, lead, manganese, and mercury bromate among others.

Bromic acid acts as an important intermediate in the Bélousov-Zhabotinsky reaction (Morris, 2010). This reaction is an example of chemical clocks and illustrates a thermodynamic non-equilibrium reaction.

The oscillation reaction is catalyzed by cerium and is inherently connected to the chemistry of bromine oxo acids HBrOx. The growing interest in nonlinear chemical systems has provided strong incentives to study the chemistry of bromine.

In the Belousov-Zhabotinsky reaction, the bromine compounds involved are hypobromous acid HOBr, bromous acid HOBrO and bromic acid HBrO3 (3) (Rainer Glaser, 2013).

Figure 3: Belousov-Zhabotinsky reaction.

These types of reactions are important for theoretical chemistry. They show that chemical reactions do not have to be dominated by equilibrium thermodynamic behavior.

References

  1. Bromic Acid. (SF). Recovered from chemyq.com.
  2. EMBL-EBI. (2008, May 16). bromic acid. Recovered from ebi.ac.uk.
  3. EMBL-EBI. (2014, July 28). chloric acid. Recovered from ebi.ac.uk.
  4. Morris, S. (2010, January 23). Belousov Zhabotinsky reaction 8 x normal speed. Recovered from youtubecom.
  5. My Favorite Chemicals. (SF). Recovered from bromicacid.com.
  6. National Center for Biotechnology Information. (2017, March 11). PubChem Compound Database; CID = 24445,. Retrieved from PubChem.
  7. Rainer Glaser, MD (2013). Why the Acidity of Bromic Acid Really Matters for Kinetic Models of Belousov-Zhabotinsky Oscillating Chemical Reactions. Journal of Thermodynamics & Catalysis 4: 1. 
  8. Royal Society of Chemistry. (2015). Bromic acid. Recovered from chemspider.com.
  9. Watts, H. (1870). A Dictionary of Chemistry and Allied Branches of Other Sciences, Volume 1. London: longmans, green and co.

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