You may be aware of the emergency oxygen masks that the air hostess keeps mentioning. Have you ever wondered from where do these masks get oxygen during an emergency?
When airlines are looking for more ways to save operational costs and fill the plane to its maximum capacity, using bulky oxygen tanks on board is really impractical. So what do the airlines do? You will be surprised to know that these oxygen masks can create their own oxygen! No magic. Pure science.
In nature, there are many non-gaseous chemicals which are rich in oxygen, such as O3 present in sodium chlorate (chemical formula, NaClO3).
When sodium chlorate/ potassium perchlorate/ barium oxide is heated a little they quickly give off its oxygen atoms, thus allowing you to have the air to breathe. This is the reason the flight attendants give instruction to you to tug on the side flaps of the mask, which creates a small explosion to generate the required heat to make the chemical release its oxygen.
Typically, the chemical reaction lasts only for 20 minutes maximum. But this time is usually enough to descend the plane to an altitude where safe breathing is possible.
You must also remember that it takes only about 30 seconds to pass out in the airline cabin with dangerously low oxygen pressure. So, you have to put your mask on as soon as possible. The airplane video below can save your life in such situations.