Also called
soda ash. an anhydrous, grayish-white, odorless, water-soluble powder, Na
2 CO
3 , 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.