How does baking powder function as a leavening agent?

Baking powder acts as a leavening agent by releasing carbon dioxide gas when combined with a liquid. This gas gets trapped in the batter or dough, causing it to rise and become light and fluffy.

The chemical process behind baking powder's action involves two main components:

1. Sodium Bicarbonate (Baking Soda): Baking powder contains sodium bicarbonate, which is an alkaline compound. When baking powder is mixed with a liquid, the sodium bicarbonate reacts with the acids present in the mixture.

2. Acidic Ingredients: Baking powder typically contains one or more acidic ingredients, such as cream of tartar, monocalcium phosphate, or sodium aluminum phosphate. These acidic components react with sodium bicarbonate to produce carbon dioxide gas.

The reaction between sodium bicarbonate and the acids can be expressed as:

`NaHCO3 (sodium bicarbonate) + H+ (acid) -> CO2 (carbon dioxide gas) + H2O (water)`

As the carbon dioxide gas is released, it gets trapped in the batter or dough, causing it to expand and rise. This is what gives baked goods their characteristic height and fluffy texture.

Baking powder is a convenient leavening agent because it does not require separate addition of an acidic ingredient. The acids required for the reaction are already incorporated into the baking powder, making it a self-rising ingredient.

It's important to note that baking powder should not be confused with baking soda. While both contain sodium bicarbonate, baking powder also includes the necessary acidic ingredients, whereas baking soda requires an additional acidic component to produce carbon dioxide gas.