Sodium hydroxide CAS 1310-73-2

The pure anhydrous sodium hydroxide is a white translucent crystalline solid. It has strong corrosivity and water absorption, and can be used as a desiccant, but it can not dry sulfur dioxide, carbon dioxide and hydrogen chloride gas. It is easy to deliquescence in the air, and sodium hydroxide is extremely soluble in water. Its solubility increases with the increase of temperature. When it is dissolved, it can release a lot of heat. At 288K, its saturated solution concentration can reach 16.4 mol/L (1:1). Its aqueous solution has astringent taste and greasy feeling. The solution is strong alkaline and has all the general properties of alkali. There are two kinds of caustic soda on the market: solid and liquid: pure solid caustic soda is white, in the form of block, sheet, rod and granular chemicalbook, which is brittle; Pure liquid caustic soda is colorless and transparent liquid. Sodium hydroxide is also soluble in ethanol and glycerol; However, it is insoluble in ether, acetone and liquid ammonia. It is corrosive to fibers, skin, glass, ceramics, etc., and will emit heat when dissolved or diluted with concentrated solution; Neutralization reaction with inorganic acids can also generate a large amount of heat and generate corresponding salts; React with metal aluminum and zinc, non-metallic boron and silicon to release hydrogen; It disproportionates with chlorine, bromine, iodine and other halogens. It can precipitate metal ions from aqueous solution into hydroxide; It can make the oil saponify and produce the corresponding organic acid sodium salt and alcohol, which is the principle of removing the oil stain on the fabric.