sodium carbonate

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A white powdery compound, Na₂CO₃, used in the manufacture of baking soda, sodium nitrate, glass, ceramics, detergents, and soap.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun chemistry A salt, Na2CO3 formally derived from sodium hydroxide and carbonic acid; it is a white powder, soluble in water, with domestic, commercial and industrial uses; it occurs naturally as natrite

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a sodium salt of carbonic acid; used in making soap powders and glass and paper