Sodium chloride is an inorganic ionic compound with the chemical formula NaCl, colorless cubic crystal or fine crystalline powder, salty taste. The appearance is white crystalline, and its source is mainly seawater, which is the main component of salt. Soluble in water, glycerin, slightly soluble in ethanol (alcohol), liquid ammonia; Insoluble in concentrated hydrochloric acid. Impure sodium chloride is deliquescent in air. The stability is relatively good, its aqueous solution is neutral, the industry generally uses the method of electrolytic saturated sodium chloride solution to produce hydrogen, chlorine and caustic soda (sodium hydroxide) and other chemical products (generally known as chlor-alkali industry) can also be used for ore smelting (electrolytic molten sodium chloride crystals to produce active sodium metal), medical use to prepare normal saline, life can be used for condiments.