Etymology: “Soda” in European languages probably comes from the Arabic “suwwad” – a common name for various types of solyanka, plants from the ashes of which it was extracted in the Middle Ages. Soda ash (sodium carbonate) is so called because to obtain it from crystalline hydrate, the latter is “calcined” (Latin: calcinatio, from calx, similar to the process of calcination of lime), that is, they are calcined.

Properties: It appears as colorless crystals or white powder. It exists in several different modifications: the α-modification with a monoclinic crystal lattice is formed at temperatures up to 350 °C, then, when heated above this temperature and up to 479 °C, it transforms into the β-modification, which also has a monoclinic crystal lattice. The Mohs hardness of sodium carbonate monohydrate is 1.3. When the temperature increases above 479 °C, the compound undergoes a γ-modification with a hexagonal lattice. It melts at 854 °C; when heated above 1000 °C, it decomposes to form sodium oxide and carbon dioxide.

Soda ash: Soda ash—technical sodium carbonate, produced in the form of grade A (granulated) and grade B (powdered) according to GOST 5100-85 with Na2CO3 content from 99.0 to 99.4%, as well as from nepheline ore (GOST 10689-75) with Na2CO3 content from 87.0 to 96.5%. A hygroscopic product, in air it absorbs water vapor and carbon dioxide to form sour salt sodium bicarbonate, and cakes when stored outdoors.

Safety

 Maximum permissible:  concentration aerosol soda ash in the air of industrial premises – 2 mg/m³. Soda ash belongs to substances of the 3rd hazard class. An aerosol of soda ash can cause irritation if it comes into contact with wet skin and mucous membranes of the eyes and nose, and if exposed for a long time -dermatitis.