Question

what are halogens?? what are it's uses?? ​

Answer 1

Answer:

Fluorine, chlorine, bromine, iodine and the more recently discovered radioactive element astatine, make up the family of elements known as the halogens. Except for astatine, the physical and chemical properties of these elements have been exhaustively studied. They occupy group VII in the periodic table, and they display an almost perfect gradation in physical properties.

The family relationship of the halogens is illustrated also by the similarity in the chemical properties of the elements, a similarity which is associated with the arrangement of seven electrons in the outer shell of the atomic structure of each of the elements in the group. All the members form compounds with hydrogen, and the readiness with which union occurs decreases as the atomic weight increases. In like manner, the heats of formation of the various salts decrease with the increasing atomic weights of the halogens. The properties of the halogen acids and their salts show as striking a relationship; the similarity is apparent in organic halogen compounds, but, as the compound becomes chemically more complex, the characteristics and influences of other components of the molecule may mask or modify the gradation of properties.

Uses

Halogens are used in the chemical, water and sanitation, plastics, pharmaceutical, pulp and paper, textile, military and oil industries. Bromine, chlorine, fluorine and iodine are chemical intermediates, bleaching agents and disinfectants. Both bromine and chlorine are used in the textile industry for bleaching and shrink-proofing wool. Bromine is also used in gold mining extraction processes and in oil- and gas-well drilling. It is a fire retardant in the plastics industry and an intermediate in the manufacture of hydraulic fluids, refrigerating and dehumidifying agents, and hair-waving preparations. Bromine is also a component of military gas and fire-extinguishing fluids.

Chlorine is used as a disinfectant for refuse and in the purification and treatment of drinking water and swimming pools. It is a bleaching agent in laundries and in the pulp and paper industry. Chlorine is used in the manufacture of special batteries and chlorinated hydrocarbons, and in the processing of meat, vegetables, fish and fruit. In addition, it acts as a flame retardant. Chlorine dioxide is utilized in the water and sanitation and swimming pool industries for water purification, taste and odour control. It is a bleaching agent in the food, leather, textile, and pulp and paper industries, as well as an oxidizing agent, bactericide and antiseptic. It is used in cleaning and detanning leather and in bleaching cellulose, oils and beeswax. Nitrogen trichloride was formerly used as a bleach and “improver” for flour. Iodine is also a disinfectant in the water and sanitation industry, and acts as a chemical intermediate for inorganic iodides, potassium iodide, and organic iodine compounds.

Fluorine, fluorine monoxide, bromine pentafluoride and chlorine trifluoride are oxidizers for rocket fuel systems. Fluorine is also used in the conversion of uranium tetrafluoride to uranium hexafluoride, and chlorine trifluoride is used in nuclear reactor fuel and for cutting oil-well tubes.

Calcium fluoride, found in the mineral fluorspar, is the primary source of fluorine and its compounds. It is used in ferrous metallurgy as a flux to increase fluidity of the slag. Calcium fluoride is also found in the optical, glass and electronics industries.

Hydrogen bromide and its aqueous solutions are useful for manufacturing organic and inorganic bromides and as reducing agents and catalysts. They are also used in the alkylation of aromatic compounds. Potassium bromide is used to manufacture photographic papers and plates. Large quantities of phosgene gas are required for numerous industrial syntheses, including the manufacture of dye-stuffs. Phosgene is also used in military gas and in pharmaceuticals. Phosgene is found in insecticides and fumigants.

Answer 2

The halogen elements are the six elements in Group 17 of the periodic table.

Uses of halogens:
Chlorine is used to purify water. Chlorine also is part of salt, sodium chloride, which is one of the most widely used chemical compounds. Fluorine is used in fluorides, which are added to water supplies to prevent tooth decay. Iodine is used as an antiseptic.