Chemical element, symbol Cl, with atomic number 17 and atomic weight 35.453. Chlorine exists as a yellow-green gas at ordinary temperatures and pressures. Chlorine is one of the four closely related chemical elements that have been called halogens.
It is widely used in water treatment due to its high efficacy against bacteria, algae, mold, fungi and microorganisms dangerous to human health. In addition, it is a bleaching agent. Its appearance is grainy, light beige in color. In aqueous solution it gives off an odor similar to that of sodium hypochlorite. The molecular weight of calcium hypochlorite is 142.98 g / mol.
Given its high antiseptic power, it is used as a disinfecting agent for swimming pool water, mainly in concentrations of 70% .1 For this reason, it is commonly called chlorine for swimming pools.