1s² 2s²p⁶ 3s²p⁶d¹⁰ 4s²p⁵

Applications

Bromine is the only liquid nonmetallic  element at room temperature and one of five elements on the period table that are liquid at or close to room temperature.   The pure chemical element has the physical form of a diatomic molecule, Br₂.   It is a heavy, mobile, reddish-brown liquid, that evaporates easily at standard temperature and pressues (273^oK & 1 Atm.) in a red vapor (its color resembles Nitrogen Dioxide, NO₂) that has a strong disagreeable odor resembling that of Chlorine.  A halogen, Bromine resembles Chlorine chemically but is less active.  It is more active than Iodine, however.  Bromine is slightly soluble in water, and highly soluble in Carbon Disulfide, CS₂, aliphatic alchohols (such as Methanol (CH₃OH), and Acetic Acid, CH₃COOH.  It bonds easily with many elements and has a strong bleaching action.

Bromine is highly reactive and is a powerful oxidizing agent in the presence of water.   It reacts vigorously with Amines, Alkenes and Phenols as well as aliphatic and Aromatic Hydrocarbons, Ketones and Acids (these are brominated by either addition or substitution reactions).  With many of the metals and elements, anhydrous Bromine is less reactive than hydrated Bromine; however, dry Bromine reacts vigorously with Aluminum, Titanium, Mercury, as well as alkaline earth metals and alkaline metals.

Elemental Bromine is used to manufacture a wide variety of Bromine compounds used in industry and agriculture.  Traditionally the largest use of bromine was in the production of 1,2-Dibromoethane which in turn was used as a gasoline anti-knock agent for leaded gasolines before they were largely phased out due to environmental considerations.

Bromine is also used in the manufacture of fumigants, brominated flame-retardants, water purification compounds, dyes, medicines, sanitizers, imorganic bromides for photography, etc.  It is also used to form intermediates in organic synthesis, where it is preferred to Iodine due to its much lower cost.

Bromine is used to make brominated vegetable oil, which is used as an emulsifier in many citrus-flavored soft drinks.

Aqueous Bromine is orange and can be used in tests for Alkenes and Phenols.

• When added to an alkene it will lose its color as it reacts forming a colorless Bromoalkane.  For example, reaction with ethylene will produce 1,2-Dibromoethane.  
• When added to phenol a white precipitate, 2,4,6-Tribromophenol, will form.  With Aniline, 2,4,6 Tribromoaniline will precipitate (even in water).

Occurrence

Bromine occurs in nature as bromide salts in very diffuse amounts in crustal rock.   Due to leaching, bromide salts have accumulated in sea water (85 ppm), and may be economically recovered from brine wells and the Dead Sea (up to 5000 ppm).  Due to its contribution to Ozone depletion in Earth's atmosphere, Bromine has been evaluated to have an Ozone depletion potential of 60 when compared to Chlorine.

Approximately 500 million kilograms ($350 million USD) of Bromine are produced per year (2001) worldwide with the United States and Israel being the primary producers.  The largest Bromine reserve in the United States is located in Columbia and Union County, Arkansas.

Safety

Elemental Bromine is a strong irritant and, in concentrated form, will produce painful blisters on exposed skin and especially mucous membranes.  Even low concentrations of Bromine vapor (from 10 ppm) can affect breathing, and inhalation of significant amounts of Bromine can seriously damage the respiratory system.

It is the only non-metal that is a liquid at normal room conditions. Bromine on the skin causes painful burns that heal very slowly.  It is an element to be treated with the utmost respect in the laboratory.  Accordingly, one should always wear safety gogglesand ensure adequate ventilation when handling Bromine.

In laboratory settings, bromine should always be kept separate from Acetone, CH₃COCH₃, as the two chemicals will react and create Bromoacetone, a potentially hazardous lachrymatory agent.

Elemental Bromine is a hazardous material.  It causes severe burns when it comes in contact with the skin and its vapor irritates the eyes, nose and throat.  Most of the Bromine produced in the United States was used in the manufacture of Ethylene Dibromide(C₂H₄Br₂), a chemical added to leaded gasolines that prevented the accumulation of lead compounds within the engine.  With the discontinuation of leaded gasolines in favor of unleaded gasolines, the demand for Bromine has been greatly reduced.  Silver Bromide (AgBr), a chemical used in photography, now accounts for the largest use of Bromine.  Other Bromine compounds are used in fumigants, in flameproofing agents and in some compounds used to purify water.  Tyrian purple, an expensive purple dye known to ancient civilizations, was produced from an organic Bromine compound secreted from a sea mussel known as the murex.

Compounds

Isotopes

(Gr. bromos, stench) Discovered by Balard in 1826, but not prepared in quantity until 1860.  A member of the halogen group of elements, it is obtained from natural brines from wells in Michigan and Arkansas.  Little bromine is extracted today from seawater, which contains only about 85 ppm.  Bromine is the only liquid nonmetallic element.  It is a heavy, mobile, reddish-brown liquid, volatilizing readily at room temperature to a red vapor with a strong disagreeable odor, resembling chlorine, and having a very irritating effect on the eyes and throat; it is readily soluble in water or carbon disulfide, forming a red solution, is less active than chlorine but more so than iodine; it unites readily with many elements and has a bleaching action; when spilled on the skin it produces painful sores.  It presents a serious health hazard, and maximum safety precautions should be taken when handling it.  Much of the bromine output in the U.S. was used in the production of ethylene dibromide, a lead scavenger used in making gasoline antiknock compounds.  Lead in gasoline, however, has been drastically reduced, due to environmental considerations.  This will greatly affect future production of bromine.  Bromine is also used in making fumigants, flameproofing agents, water purification compounds, dyes, medicinals, sanitizers, inorganic bromides for photography, etc. Organic bromides are also important.

Source: CRC Handbook of Chemistry and Physics, 1913-1995. David R. Lide, Editor in Chief. Author: C.R. Hammond