Bromine . Poisonous element that at room temperature has a dark red color. It is one of the halogens and belongs to group 17 (or VII A) of the periodic system. Its atomic number is 35. Extremely volatile element.
Properties and natural state
Bromine is abundantly found in nature. Its melting point is -7.25 ° C, and its boiling point is 58.78 ° C, its relative density being 3.10 g / cm3 and its atomic mass 79.90. Due to its chemical properties, bromine is so similar to the chlorine with which it is almost always associated that it was not recognized as a distinct element until 1826 , when it was isolated by the French chemist Antoine Jérome Balard.
Bromine is an extremely volatile liquid at room temperature; releases a reddish vapor composed of diatomic molecules.
In contact with the skin, it produces very slow healing wounds. It is slightly soluble in water, 100 parts of water dissolve about 4 parts of bromine when cold and about three parts when hot. At temperatures below 7 ° C, together with water, it forms a solid, red hydrate Br 2 • 10H 2 O.
In the presence of alkalis, bromine chemically reacts with water to form a mixture of hydrobromic acid (HBr) and hypobromous acid (HOBr). Bromine is readily soluble in a wide variety of organic solvents, such as alcohol, ether, trichloromethane (chloroform), and carbon disulfide. It reacts chemically with many metallic compounds and elements, and is slightly less active than chlorine.
Bromine is not found in nature in its pure state, but in the form of compounds. The bromine can be obtained from the bromide by treatment with manganese dioxide or sodium chlorate . Increased demand has led to the production of bromine from seawater, which contains a proportion of 65 parts of bromine per million.
Applications
Bromine has been used in the preparation of certain dyes and in obtaining dibromoethane (ethylene bromide), a component of the antiknock liquid in lead gasoline. It also has applications in Photography and in the production of Natural Gas and Petroleum