Sciencemadness Discussion Board

Sodium Carbonate

lvjrf - 26-9-2004 at 22:48

Hi all

what is the differnce between Sodium Carbonate (Soda Ash) which used in soaps
and Sodium carbonate which used in food (bread) ?

JohnWW - 27-9-2004 at 00:16

"Soda ash" refers to anhydrous Na2CO3, obtained by dehydration of hydrous forms, or by the Solvay process (which results in a product containing about 1% impurities, these consisting of sulfate and chloride and silicate). It is used in soaps, petroleum refining, paper manufacture, ceramics, glass-making, and making other Na salts.

Sodium carbonate can be also crystallized from saturated solutions as either the monohydrate, heptahydrate, and decahydrate, depending on the temperature. Sal soda, or washing soda, is usually the decahydrate, Na2CO3.10H20, although the other hydrates are also used for the same purpose; the monohydrate is also used in photography.

That used in baking is usually baking soda, sodium bicarbonate, NaHCO3. A similar mixed carbonate is trona, Na3H(CO3)2.2H2O, which occurs as a mineral in northeast Africa. The ancient Egyptians used it for mummifying bodies.

John W.

Thanks Mr. JohnWW

lvjrf - 27-9-2004 at 01:14

Good report