Sodium chloride /ˌsoʊdiəm ˈklɔːraɪd/, [8] commonly known as edible salt, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chlorine ions. It is transparent or translucent, brittle, hygroscopic, and occurs as the mineral halite. In its edible form, it is commonly used as a condiment and food preservative. Large quantities of sodium chloride are used in many industrial processes, and it is a major source of sodium and chlorine compounds used as feedstocks for further chemical syntheses. Another major application of sodium chloride is deicing of roadways in sub-freezing weather. Uses In addition to the familiar domestic uses of salt, more dominant applications of the approximately 250 million tonnes per year production (2008 data) include chemicals and de-icing.[9] Chemical functions Salt is used, directly or indirectly, in the production of many chemicals, which consume most of the world's production.[10] Chlor-alkali industry See also: Chloralkali process It is the starting point for the chloralkali process, the industrial process to produce chlorine and sodium hydroxide, according to the chemical equation 2 NaCl + 2 H 2 O → e l e c t r o l y s i s Cl 2 + H 2 + 2 NaOH {\displaystyle {\ce {2 NaCl + 2 H2O ->[electrolysis] Cl2 + H2 + 2 NaOH}}} This electrolysis is conducted in either a mercury cell, a diaphragm cell, or a membrane cell. Each of those uses a different method to separate the chlorine from the sodium hydroxide. Other technologies are under development due to the high energy consumption of the electrolysis, whereby small improvements in the efficiency can have large economic paybacks. Some applications of chlorine include PVC thermoplastics production, disinfectants, and solvents. Sodium hydroxide is extensively used in many different industries enabling production of paper, soap, and aluminium etc.