Have you ever wondered where they store the oxygen for the emergency masks aboard airplanes? With airlines finding more ways to save costs and fill the plane to capacity, it would be impractical to use heavy, bulky oxygen tanks. Especially when there's another way: create your own oxygen.
There are plenty of non-gas chemicals that are rich in oxygen—take a look at the O3 in sodium chlorate's chemical formula, NaClO3, for example. All it needs is a little bit of heat, and sodium chlorate (or barium peroxide, or potassium perchlorate) quickly gives off its oxygen atoms so that you have air to breathe. That's why flight attendants instruct you to tug on the mask. That tug creates a small explosion that will generate the heat it takes to make the chemical in question release its oxygen. The chemical reaction only lasts for a maximum of about 20 minutes, but that's usually enough time for the plane to descend to a safe breathing altitude. Still, it's extremely important that you put your mask on as soon as possible, since it only takes about 30 seconds in dangerously low cabin pressure for a person to pass out. Attention all passengers, we would now like to direct your attention to the airplane videos below.