Pure products are colorless and transparent crystals. The density is 2.130g/cm3. The melting point is 318.4℃. Boiling point 1390 ℃. Industrial products contain a small amount of sodium chloride and sodium carbonate, which are white opaque crystals. There are blocks, flakes, granules and rods, etc. Formula weight 39.997. Sodium hydroxide can be used as an alkaline cleaning agent in water treatment, soluble in ethanol and glycerol; insoluble in propanol and ether. It reacts with halogens such as chlorine, bromine and iodine by disproportionation. Neutralizes with acids to generate salt and water.
Sodium hydroxide has long been known as an alkaline substance. In 1787, physician Nicolas Leblanc (1762-1806) invented a suitable process for preparing sodium hydroxide from table salt, and carried out large-scale production. In 1887, the Swedish chemist Arrhenius established the theory of acid-base ionization (that is, the acid-base theory of aqueous solutions). All the anions generated by ionization are hydroxide ions.
Since then, the alkalinity of sodium hydroxide has been clearly defined. Pure anhydrous sodium hydroxide is a white translucent, crystalline solid. Sodium hydroxide is very soluble in water, and its solubility increases with the increase of temperature. It can release a lot of heat when it dissolves. At 288K, its saturated solution concentration can reach 16.4mol/L (1:1). Its aqueous solution has astringency and greasy feeling, the solution is strong alkaline, can react with acidic substances, and has all the properties of alkali. There are two kinds of caustic soda available in the market: solid and liquid: pure solid caustic soda is white, in block, flake, rod, granular, and brittle; pure liquid caustic soda is colorless and transparent liquid.
Sodium hydroxide, the chemical formula is NaOH, commonly known as caustic soda, caustic soda, caustic soda, is a strong corrosive alkali, generally in the shape of flakes or blocks, easily soluble in water (dissolving in water, exothermic) and It forms an alkaline solution and has deliquescence, which is easy to absorb water vapor (deliquescence) and carbon dioxide (deliquescence) in the air. NaOH is an essential chemical in chemical laboratories, and it is also one of the common chemicals.
