Do things need to be under pressure to explode?

Question

If you put gasoline vapors with the right amount of oxygen in a paper bag will it expolde?

Answer 1

Gasoline and many other vapors or dusts will explode in air at atmospheric pressure at the proper concentration. Explosive force can be concentrated by containing it, because the pressure will go higher than a free-air explosion. Some things, black powder for example, don't have much explosive force unless you detonate them in a sealed container. On the other hand, anything classified as "high explosive" will produce a destructive blast wave in open air.

Answer 2

Yes it willlll...and it will blow the windows out of your house at the same time...If your considering this remember that the more restrictive your enclosure the farther your limp body will be thrown...Gasoline ,natural gas ,propane etc....all have a very explosive quality that when combined with Oxygen will for real hurt you...Read the history of Nobel and what he found out in his experiments...
http://www.lucidcafe.com/library/95oct/alfnobel.html
Have a safe Happy Thanksgiving...from the E..

Answer 3

you don't need to put things under pressure to explode. The main thing is the gas must be highly reactive to oxygen or heat.

Example: lighting up a match in a room full of hydrogen gas
(DON'T ever be this reckless to try this yourself!)