sodium carbonate

Also called soda ash. an anhydrous, grayish-white, odorless, water-soluble powder, Na₂CO₃, usually obtained by the Solvay process and containing about 1 percent of impurities consisting of sulfates, chlorides, and bicarbonates of sodium: used in the manufacture of glass, ceramics, soaps, paper, petroleum products, sodium salts, as a cleanser, for bleaching, and in water treatment.

Also called sal soda, soda, washing soda. the decahydrated form of this salt, Na₂CO₃⋅10H₂O, used similarly.

the monohydrated form of this salt, Na₂CO₃⋅H₂O, used similarly, especially in photography.