Chemical leaveners are substances used in baking to produce gas, which helps dough or batter rise. Common examples include baking soda and baking powder. When these leaveners react with moisture and heat, they release carbon dioxide gas, creating bubbles that expand and lighten the texture of baked goods. Baking soda is a base that requires an acid, such as vinegar or buttermilk, to activate its leavening properties. In contrast, baking powder contains both an acid and a base, allowing it to work independently when mixed with liquid. Both types are essential for achieving the desired fluffiness in recipes like cakes and muffins.