See iwnit1's answer for better explanation! Baking powder is baking soda plus cream of tartar plus cornstarch.... NaHCO3. baking soda Cream of tartar KHC4H4O6. Rxn: NaHCO3 + KHC4H4O6 ----> KNaC4H4O6 + H2O + CO2 Some baking powders contain sodium aluminum sulfate: NaAl(SO4)2. The reaction there is: NaAl(SO4)2 + 3 NaHCO3 ----> Al(OH)3 + 2 Na2SO4 + 3 CO2

1) "Baking powder is a dry chemical leavening agent used in baking and deodorizing. There are several formulations; all contain an alkali, typically sodium bicarbonate (baking soda), and an acid in the form of salt crystals, together with starch to keep it dry. When dissolved in water the acid and alkali react and emit carbon dioxide gas, which expands existing bubbles to leaven the mixture. Most modern baking powders are double acting, that is, they contain two acid salts, one which reacts at room temperature, producing a rise as soon as the dough or batter is prepared, and another which reacts at a higher temperature, causing a further rise during baking. Baking powders that contain only the low-temperature acid salts are called single acting. Many recipes call for a process called creaming, where butter and sugar are beaten together to introduce tiny seed bubbles which the leavening gas will further expand. Common low-temperature acid salts include cream of tartar, calcium phosphate, and citrate. High-temperature acid salts are usually aluminium salts, such as calcium aluminum phosphate. They can be found not only in many baking powders, but also in many non-dairy coffee creamers. Excess aluminium in the diet may be detrimental to human health, and so baking powders are available without it for people who are concerned and those sensitive to the taste." Source and further information: http://en.wikipedia.org/wiki/Baking_powder 2) "What is baking powder and how does it work? If you have read How Bread Works, then you understand how the release of carbon dioxide by yeast can cause bread to rise. Many recipes, however, use no yeast. Things like muffins, biscuits, cakes and cookies usually use baking powder instead. Baking powder is normally made of three different parts: An acid A base A filler of some sort All three need to be dry powders that can be mixed together. For example, baking soda (a base), cream of tartar (an acid) and corn starch (the filler) are three common ingredients. In school, you may have done the experiment where you mix baking soda (a base) and vinegar (an acid) and get a bubbling reaction. Baking powder works the same way. When you add water to baking powder, the dry acid and base go into solution and start reacting to produce carbon dioxide bubbles. Single-acting baking powder produces all of its bubbles when it gets wet. Double-acting baking powder produces bubbles again when it gets hot. If you want to prove to yourself that this is how baking powder works, simply try mixing a teaspoon of baking powder into a cup of hot water. As long as the baking powder is fresh, you will definitely see the reaction! Baking soda, also known as sodium bicarbonate, has the chemical formula NaHCO3. Cream of tartar, also known as tartrate salt, has the formula KHC4H4O6. The reaction is: NaHCO3 + KHC4H4O6 ----> KNaC4H4O6 + H2O + CO2 Some baking powders contain sodium aluminum sulfate: NaAl(SO4)2. The reaction there is: NaAl(SO4)2 + 3 NaHCO3 ----> Al(OH)3 + 2 Na2SO4 + 3 CO2 Many recipes call simply for baking soda rather than baking powder. Usually these recipes use some kind of liquid acid like buttermilk or yogurt to react with the baking soda to produce the bubbles. The reason why people often prefer baking powder to yeast is because yeast takes so long -- usually two to three hours -- to produce its bubbles. Baking powder is instant, so you can mix up a batch of biscuits and eat them 15 minutes later." Source and further information: http://www.howstuffworks.com/question57.htm 3) Further information: "Baking powder is actually a combination of baking soda, cream of tartar and a bit of cornstarch." http://www.slashfood.com/2006/05/09/baking-powder-vs-baking-soda/ http://www.fineli.fi/food.php?foodid=74&lang=en

Sodium bicarbonate is NaHCO3

Sodium Bicarbonate+/-Tartaric Acid(plus cornflour). It can also be made of Ammonium Carbonate(Carbamate)