Sodium chloride (NaCl), chemical formula, colorless cubic crystal or fine-grained powder, with salty taste. The appearance is white crystal, and its source is mainly seawater, which is the main component of salt.

Sodium chloride is easily soluble in water and glycerol, and slightly soluble in ethanol and liquid ammonia; Insoluble in concentrated hydrochloric acid. Impure sodium chloride is easy to deliquesce in air, with good stability, and its aqueous solution is neutral.

Electrolysis of saturated sodium chloride solution is generally used in industry to produce chemical products such as hydrogen, chlorine and caustic soda (commonly known as chlor-alkali industry). It can also be used for ore smelting (electrolysis of molten sodium chloride crystals to produce active metal sodium), preparation of physiological saline in medical treatment and seasoning in life.

Extended data:

Preparation method:

Industrial methods:

Seawater (containing 2.4% sodium chloride on average) was introduced into the saltworks, dried in the sun, concentrated and crystallized to obtain crude products. Or heating seawater with steam, filtering with sand filter, concentrating with ion-exchange membrane electrodialysis to obtain brine (containing sodium chloride 160 ~ 180 g/L), then evaporating and separating brine gypsum to obtain sodium chloride greater than 95% (water content is 2%), and then drying to make salt.

Rock salt and salt lake brine can also be used as raw materials, and the raw salt can be dried. It is made from underground brine and well salt by three-effect or four-effect evaporation concentration, crystallization and centrifugal separation.

Laboratory methods:

Dissolve crude salt in water, remove insoluble impurities, and add refined agents such as sodium hydroxide and sodium carbonate. Precipitating soluble impurities such as SO42-, Ca2+ and Mg2+, filtering to remove, finally adjusting the pH to 7 with pure hydrochloric acid, and concentrating the solution to obtain pure sodium chloride crystals.

The preparation method in the laboratory is to mix equal amounts of hydrochloric acid and sodium hydroxide to generate sodium chloride solution. And then distilling the solution to obtain sodium chloride crystals. Main reaction:.

In addition, sodium metal will also produce sodium chloride when it is ignited in chlorine, and its chemical equation is:?

References:

Baidu encyclopedia-sodium chloride