Baking Science: Baking Soda and Baking Powder
Baking Powder is baking soda (sodium bicarbonate) that is already mixed with an acidic ingredients. Therefore, baking powder can be used on its own to leaven baked goods without the need for an acidic ingredient. Baking powder works in the same way that baking soda does by creating air bubbles (carbon dioxide) which cause the baked good to rise.