Why does baking powder make cakes rise?

Answer: It releases CO2 when heated

It creates air pockets — Wrong. Baking powder doesn't create air pockets mechanically. It produces carbon dioxide gas through chemical reactions. These gas bubbles then create the pockets that make cakes fluffy.

It releases CO2 when heated ✓ — Correct! Baking powder contains sodium bicarbonate (a base) and an acid (like cream of tartar). When mixed with liquid and heated, they react to produce CO2 gas. Most baking powder is 'double-acting' - it releases some CO2 when wet and more when heated. The gas expands in the oven, making cakes rise!

It adds volume to batter — Wrong. Adding volume is the result, not the cause. Baking powder works by producing carbon dioxide gas through a chemical reaction. This gas expands when heated, creating bubbles that make the cake rise and become fluffy.