Baking powder is a white substance that is added to bread and cakes to make them soft and fluffy.

Baking powder is basically a mixture of sodium bicarbonate and an acidic component usually the tartaric acid. When water is added to the baking powder, it releases carbon dioxide gas that raises the volume of the baked goods.

Thus, the baking powder is sodium bicarbonate and its molecular formula is ${\mathrm{NaHCO}}_3$.