What's better than walking inside your house to the nice warm delicious smell of cookies coming out of the oven? Or freshly frosted cupcakes sitting on the counter? We can barely wait to dig our teeth into the moist and fluffy confections. But what makes sweet treats like cakes, cookies, and cupcakes so fluffy and light? Dare we say… chemistry?
The real secret ingredient to light and fluffy, melt-in-your-mouth deserts is baking soda, or to be more chemically specific, sodium bicarbonate. Baking soda has a chemical formula of NaHCO3 and is used in everything from cooking and cleaning to treating heartburn and indigestion.
How does this simple little compound do so much work in our kitchens? When baking soda is used in baking recipes it makes batter rise, which results in a light and fluffy texture. This occurs because baking soda decomposes upon heating to form carbon dioxide (a gas) according to the following equation:
2 NaHCO3 → Na2CO3 + CO2 + H2O
Let's try out a stoichiometry question. (C'mon you knew it was coming, didn't you?)
According to our grandmother's favorite the-berry-best-strawberry cupcake recipe we need 1.5 grams of baking soda for two-dozen cupcakes. If we make five-dozen cupcakes how much CO2 (in grams) will we produce?
First of all let's figure out how many moles of baking soda we need for five-dozen cupcakes:
Did you notice how we pulled a 1.5 g baking soda to every two-dozen cupcakes conversion factor out of the problem? Now let's convert to grams of CO2.
If you feel adventurous, try baking some cupcakes or cookies without baking soda next time. We have a feeling you're going to end up with some very disappointing results.