Sodium Carbonate (CAS No. 497-19-8) is an inorganic compound with a chemical formula of Na2CO3 and a molecular weight of 105.99. It is also called soda ash, but it is classified as a salt rather than an alkali. Also known as soda or soda ash in international trade Sodium carbonate is white odorless powder or granules at room temperature. It has water absorption, and gradually absorbs 1mol/L moisture (about = 15%) when exposed to the air. Sodium carbonate is easily soluble in water and glycerol. The aqueous solution of sodium carbonate is alkaline and corrosive to a certain extent and can undergo a metathesis reaction with acid, as well as a metathesis reaction with some calcium salts and barium salts. The solution is alkaline, which can make phenolphthalein turn red.