What's the difference between baking powder and baking soda?

Like, for example, while baking cookies, does it matter?What's the difference between baking powder and baking soda?
Baking Powder is the mix, soda is pure sodium bicarbonate.





When you are working with highly acidic foods, baking soda will work by itself, and remove some of the tartness, but never in the same concentration as baking powder. More like 1/4 tsp per cup of flour.





Powder has an acidic salt in it to help it produce gas when it's moistened. Use one tsp per cup of flour.





NEVER substitute soda for powder. The results are awful.What's the difference between baking powder and baking soda?
Baking Soda





Baking soda is pure sodium bicarbonate. When baking soda is combined with moisture and an acidic ingredient (e.g., yogurt, chocolate, buttermilk, honey), the resulting chemical reaction produces bubbles of carbon dioxide that expand under oven temperatures, causing baked goods to rise. The reaction begins immediately upon mixing the ingredients, so you need to bake recipes which call for baking soda immediately, or else they will fall flat!





Baking Powder





Baking powder contains sodium bicarbonate, but it includes the acidifying agent already (cream of tartar), and also a drying agent (usually starch).





Baking powder is available as single-acting baking powder and as double-acting baking powder. Single-acting powders are activated by moisture, so you must bake recipes which include this product immediately after mixing. Double-acting powders react in two phases and can stand for a while before baking. With double-acting powder, some gas is released at room temperature when the powder is added to dough, but the majority of the gas is released after the temperature of the dough increases in the oven.
Summary


Baking soda and/or baking powder are added to batters for leavening; i.e., in order to produce the gas that make cakes, muffins, and quick breads rise.





Baking soda + liquid acid (in the recipe) ---%26gt; leavening





Single-acting baking powder = baking soda + a dry acid. When the liquid ingredients are mixed with the dry ingredients you get leavening --OR-- when the product is heated you get leavening.





Double-Acting baking powder = baking soda + 2 dry acids. When the liquid is added you get leavening --PLUS-- when the product is heated you get leavening.
I have attached a link to your answer....





This is an awesome website.....
A leaven is anything that produces bubbles in dough or batter, causing baked goods to rise. Most breads rise because of yeast, which works by fermenting sugar, which in turn produces carbon dioxide. Baking soda and baking powder are used to leaven quick breads, cookies, and muffins. Baking *soda* is alkaline and reacts with acid to create carbon dioxide bubbles that become trapped within the batter. It's sometimes used in batters that contain acidic ingredients, like buttermilk or molasses. --If there's not enough acid in the batter, the recipe will instead call for baking *powder*, which combines baking soda with one or more acidic salts. When the baking powder becomes wet or sufficiently hot, the soda reacts with the salts and releases bubbles
baking powder does not have salt in it baking soda does. if the recipe calls for baking soda you can use baking powder and add salt but not the reverse.