He Bromic acid , Also known as hydrogen bromate or bromic acid (V), is a chemical compound of the formula HBrO3.
Brromic acid 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).
Figure 1: structure of the brómico acid.
It behaves like a Brownsted acid capable of donating a proton. It is a highly unstable compound that decomposes easily into the bromine element (Bromic Acid, S.F.).
To prepare bromic acid, a soluble bromate is usually dissolved in water and a soluble barium salt is added. Precipitate barium bromide sparingly soluble. The barium bromate can then be dissolved in water and acidified with sulfuric acid to precipitate the basically insoluble barium sulphate and leave behind the chromic acid (see above):
2KBrO 3 (aq) + BaCl 2 (aq) -> Ba (BrO 3) 2 (s) + 2KCl (aq)
Ba (BrO 3) 2 (aq) + H 2 SO 4 (aq) -> 2HBrO 3 + BaSO 4
The compound may also be produced by the decomposition of bromine pentachloride in alkaline solution according to the reaction:
BrCl 5 + 3 H 2 O → HBrO 3 + 5 HCl
Brromic 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 Teflon tube trapped in the fire (My Favorite Chemicals, S.F.).
You may also be interested in learning more about Bromous acid: properties and uses .
Physical and chemical properties of bromic acid
Brromic acid exists only in a colorless solution (up to 50% w / v) that turns yellow in contact with air (National Center for Biotechnology Information, 2017). Their appearance is shown in figure 2.
Figure 2: appearance of the brómico 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 by means of 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 decomposes forming acetic acid in an exothermic reaction. It is essential for the preparation of the bromate salts (BrO 3 -) which are prepared by reacting the carbonates or oxides of the metals with bromic acid (Watts, 1870).
Reactivity and hazards
Brromic 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), contact with the eyes (irritant) and in case of ingestion. Very hazardous also in case of inhalation.
Severe overexposure may result in lung damage, asphyxia, loss of consciousness or death. Prolonged exposure may cause skin burns and ulcerations. Overexposure by inhalation 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 may cause damage to these organs.
In case of contact with eyes
Check for contact lens wear and remove immediately. The eyes should be flushed with tap water for at least 15 minutes, keeping the eyelids open. Cold water can be used. Eye ointment should not be used.
In case of contact with skin
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 victim's exposed skin, such as the hands, gently and thoroughly wash contaminated skin 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 contact with the skin is severe, it should be washed with a disinfectant soap and cover the skin contaminated with an anti-bacterial cream.
In case of inhalation:
It is advisable to leave the victim in a well-ventilated area. If the inhalation is severe, the victim should be evacuated to a safe area as soon as possible. Loosen tight clothing such as a shirt collar, belts, or tie. If it is difficult for the victim to breathe, oxygen should be administered.
If the victim is not breathing, a mouth-to-mouth resuscitation is performed. Always taking into account that it can be dangerous for the person providing help 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 seek immediate medical attention.
Applications
Brromic acid is used as a powerful oxidizing agent in laboratory reactions. It is used to produce chemical compounds like iodates, chloric acid, tetrahonic acid among others.
It is also used for the production of bromates such as iron bromate, lead, manganese, mercury, among others.
Brômic acid acts as an important intermediary in the reaction of Bélousov-Zhabotinsky (Morris, 2010). This reaction is an example of chemical clocks and illustrates a thermodynamic non-equilibrium reaction.
The oscillation reaction is cerium catalyzed and is inherently connected to the chemistry of the bromine oxoacids HBrOx. The growing interest in nonlinear chemical systems has provided strong incentives to study bromine chemistry.
In the Belousov-Zhabotinsky reaction, the bromine compounds involved are HOBr hypobromous acid, HOBrO bromine acid and HBrO3 (3) bromic acid (Rainer Glaser, 2013).
Figure 3: Belousov-Zhabotinsky reaction.
Such reactions are important for theoretical chemistry. They show that chemical reactions do not have to be dominated by equilibrium thermodynamic behavior.
References
- Bromic Acid. (S.F.). Retrieved from chemyq.com.
- EMBL-EBI. (2008, May 16). Bromic acid. Retrieved from ebi.ac.uk.
- EMBL-EBI. (2014, July 28). Chloric acid. Retrieved from ebi.ac.uk.
- Morris, S. (2010, January 23). Belousov Zhabotinsky reaction 8 x normal speed. Recovered from youtubecom.
- My Favorite Chemicals. (S.F.). Retrieved from bromicacid.com.
- National Center for Biotechnology Information. (2017, March 11). PubChem Compound Database; CID = 24445. Recovered from PubChem.
- Rainer Glaser, M.D. (2013). Why the Acidity of Bromic Acid Really Matters for Kinetic Models of Belousov-Zhabotinsky Oscillating Chemical Reactions. Journal of Thermodynamics & Catalysis 4: 1.
- Royal Society of Chemistry. (2015). Bromic acid. Recovered from chemspider.com.
- Watts, H. (1870). A Dictionary of Chemistry and Allied Branches of Other Sciences, Volume 1. London: longmans, green and co.