Here's a really easy explosion that you may have seen before. Have you ever seen a model volcano that explodes using baking soda and vinegar? The reason that this works is because when you mix the baking
soda and vinegar there is a chemical reaction that produces lots of gas
(carbon dioxide). The gas takes up a lot more room than the solid
baking soda or the liquid vinegar, so it sends spurts of bubbles
shooting out of the top of the volcano.
Well, the same thing will happen even without model volcano to do it inside of. For instance, if you put a little bit of baking soda in one corner of a small ziploc bag and a little bit of vinegar in the other, then seal the bag and mix it up, the same reaction will occur.
Gas will be formed and it will need someplace to go, so it will have to
pop the bag open to get out. But just like with any explosion, you have
to be very careful when you’re doing this. Use /very/ small amounts of
baking soda and vinegar and use a fairly weak bag. (Sturdier plastic
bags will be harder to pop, so when they do pop it will be much more
forceful.) When you set the bag down, point the (now sealed) opening
away from you – this is the part most likely to pop open first. And, of
course, stand back.
For any sort of explosion involving fire, however, you should be
shown how to do it by someone with experience, not just read about it
on the internet. Try asking your science teacher to help you with this
(republished on 07/17/06)