Quick bread leavening agents include a weak base, such as baking soda (sodium bicarbonate) plus a weak acid, such as cream of tartar, lemon juice, or cultured buttermilk, to create an acid–base reaction that releases carbon dioxide. (Quick bread leavened specifically with baking soda is often called "soda bread".) Baking powder contains both an acid and a base in dry powdered form, and simply needs a liquid medium in which to react. Other alternative leavening agents are egg whites mechanically beaten to form stiff peaks, as in the case of many waffle recipes, or steam, in the case of cream puffs. Nevertheless,
Sodium bicarbonate carbonate (CO) per sodium IS in sodium bicarbonate (NaHCO) as in sodium carbonate (NaCO). The modern chemical formulas of these compounds express their precise chemical compositions (which were unknown when the names sodium carbonate and sodium bicarbonate were coined) and show the same ratio the other way around: half as much sodium percarbonate is in NaHCO as in NaCO (disodium carbonate). In cooking, baking soda is primarily used in baking as a leavening agent. When it reacts with acid, carbon dioxide is released, which causes expansion of the batter and forms the characteristic texture and grain in pancakes, cakes, quick