While baking soda and baking powder are essential in the kitchen and feature an anti-caking chemical called sodium bicarbonate, the two are not interchangeable.

When sodium bicarbonate interacts with an acid, it releases carbon dioxide, the chemical responsible for fluffing up baked goods. Baking soda is pure sodium bicarbonate.

However, baking powder is baking soda with an added acid. The extra ingredient in baking powder is often potassium bitartrate, otherwise known as cream of tartar.

Baking soda is a base, meaning you'll have to manually add an acid for it to react. It's ideal for marinating chicken or adding to recipes with a lot of acidity.

Since it already has acid, baking powder shines when the ingredients have higher pH values. Cake recipes use it because they have more basic/alkaline or neutral ingredients.