how air bag works in car?
Although we don't usually associate automobiles with chemistry, a lot of chemistry takes place in a working car--the burning of gasoline to run the engine, for example, and chemical reactions in the battery to generate electricity. Another reaction--one that most drivers would just as soon not experience firsthand--involves the air bag. Air bags are not inflated from some compressed gas source but rather from the products of a chemical reaction. The chemical at the heart of the air bag reaction is called sodium azide, or NaN3.Under normal circumstances, this molecule is quite stable. If heated, though, it will fall apart. The chemical equation 2 NaN3 --> 2 Na + 3 N2 describes exactly how it falls apart. Notice that the second product of the above reaction is N2, also known as nitrogen gas. A handful (130 grams) of sodium azide will produce 67 liters of nitrogen gas--which is enough to inflate a normal air bag.
0.03 SECOND is all it takes to inflate an air bag.
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That's not the only chemistry involved. Notice that the other chemical into which sodium azide falls apart is Na, or sodium. Sodium is a very reactive metal that will react rapidly with water to form sodium hydroxide; as a result, it would be quite harmful if it got into your eyes, nose or mouth. So to minimize the danger of exposure, air bag manufacturers mix the sodium azide with other chemicals that will react with the sodium and, in turn, make less toxic compounds.
What prompts an air bag to inflate by way of this reaction? There are sensors in the front of the automobile that detect a collision. These sensors send an electric signal to the canister
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