| Why does gunpowder explode when lit?|
|Question Date: 2013-09-06|
It doesn't, actually. Gunpowder burns very,
very quickly, on account of the fact that one of
its components, potassium nitrate, supplies oxygen
to the charcoal and sulfur to achieve an
accelerated burn rate. This combustion produces a
much larger volume of hot gas than the gunpowder
itself, and if that gas is in a combined space,
then it will force its way out with an explosion.
However, if the gunpowder is not in a confined
space, then it will just burn since the gas will
simply expand into the surrounding air.
Excellent question! Gunpowder is a powder mixture
of very combustible (burnable) chemicals, namely
sulfur, charcoal, and potassium nitrate.
When you light gunpowder on fire, the same
type of chemistry is happening there as when you,
for instance, burn firewood in a fireplace or
light up charcoal on a barbecue grill. Burning
materials release heat and hot gas at different
rates depending on their properties. Since
gunpowder comes in a fine powder, a lot of it is
quickly burned, resulting in a lot of hot gas and
heat being released at once. All this energy
forces the gunpowder outward, further igniting
more of it and causing the explosion that we can
What makes gunpowder seem to "explode" is
because it burns very rapidly. It seems to explode
because when it is compressed in a barrel, it is
packed in a very tiny space which means great
pressure. So when it burns very fast, in a very
confined space, the gases are built up and
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