Sodium bicarbonate and sodium carbonate act similarly in food, though sodium carbonate reacts much more strongly. Both react with acid, resulting in the production of a compound called carbonic acid, which has the chemical formula H2CO3. Carbonic acid then decomposes into carbon dioxide and water, explain Drs. Mary Campbell and Shawn Farrell in their book "Biochemistry." The carbon dioxide bubbles produce leavening action. The major difference between sodium bicarbonate and sodium carbonate in food is that while sodium bicarbonate doesn't significantly change a food's acidity, sodium carbonate makes the food very basic.