Sodium carbonate water 10 on watch glass, Sodium carbonate decahydrate; Na2CO3 10H2O; Molar mass 286.1416g/mol. Also known as washing soda, soda crystals. It is a water soluble salt, moderately alkaline, originally produced by burning plants rich in sodium. It is now produced from??odium chloride??nd??imestone??y the??olvay process. Sodium carbonate is used in the manufacture of glass, paper, rayon, soaps, and detergents and the crystals are a common household chemical used to washing clothes, soften water, clean drains and washing machines and remove moss from paths. When in solution this alkali is a base. As an anhydrous powder, Na2CO3, is also known as soda ash.