Гипобромит натрия

Description

Sodium hypobromite NaBrO is the sodium salt of hypobromous acid, a bromine analogue of hypochlorite. The compound is unstable and is marketed in solutions, including stabilized ones (the trade designation from the card is Stabrex). Function: oxidizer and biocide.

Identification

• CAS No.: 13824-96-9
• Chemical formula: BrHO Na (NaBrO)
• English name: Sodium hypobromite
• EU number: 237-520-4
• Synonyms: hypobromic acid sodium salt, sodium hypobromite (Na(BrO)), Stabrex
• Catalog section: inorganic salts

Basic Attributes

• Molecular weight: 118.89
• Exact weight: 117.903
• Polar Surface PSA: 23.1
• XLogP3: 0.7268

Chemical behavior

In aqueous solution, hypobromite is in equilibrium with hypobromous acid HOBr; it is the neutral HOBr molecule that penetrates the cell membrane and provides a biocidal effect. The key difference from hypochlorite is the higher dissociation constant of the acid: the proportion of the active form of HOBr remains at alkaline pH, while hypochlorous acid at the same values ​​​​already transforms into the low-active hypochlorite anion. The second difference is resistance to amines: bromine reacts with ammonia and amines to form bromamines, which, unlike chloramines, retain biocidal activity.

Scope of application

• oxidizing biocide in industrial refrigeration systems - suppression of bacterial fouling and biofilms in cooling towers and heat exchangers
• processing of process and waste waters
• whitening
• organic synthesis: Hoffmann rearrangement - conversion of amides of carboxylic acids into amines with loss of a carbon atom
• analytical chemistry: hypobromite method for determination of urea and nitrogen

Bromine is preferred over chlorine in water treatment due to its lower volatility and better performance at high pH and in the presence of amines. However, like sodium hypochlorite, hypobromite is unstable under normal storage conditions and is therefore supplied in a stabilized form.

Stability

The compound is relatively unstable and decomposes under the influence of heat and light with the possible release of bromine. Requires cold storage.

Safety

Strong oxidizing agent, causes corrosion and irritation of skin and mucous membranes. There are no separate H and P phrases listed on the original card for this CAS; work is carried out according to the safety data sheet of a specific supplier using gloves, safety glasses and ventilation.

Transportation and storage

• Transport codes: 1479
• Hazard category: 5.1 (oxidizing substances)
• Packing group: II
• Storage conditions: 0–6 °C

The range of 0–6 °C is not a recommendation, but a condition for maintaining commercial properties: at room temperature, the solution loses active bromine. Store in the dark, away from acids (acidification causes the release of bromine) and from reducing agents.