Gasoline question...

Please settle an argument between a friend and I. As I understand it, for gasoline to burn, it must be “atomized”, or in other words, in vapor state. The fumes actually burn, and not when it is in liquid form, because it needs oxygen to burn. However, he thinks otherwise. His argument is that it will burn in a liquid state. He thinks, that if you were to have a large container full of gasoline, and in the bottom of the container, submerged in gasoline, you had two electrodes to provide a spark, it would explode. I told him that I did not think it would explode. However it is something I will not be trying…haha…
Thanks!
:slight_smile:

It has been many years, back when I was in grade school, but I saw a demonstration on the very subject.

The details are a little hazy. One of the teachers had some sort of special glass tank he used. He put a little gas in, dropped in a match, and the vapors ignited. Then, and this is the part I really can’t remember, he somehow managed to put a match directly into the liquid gas without igniting the vapors. The match went out.

Also, some mechanics will repair a leaky gas tank by filling it full of gas and then welding the leak. If the tank is full of gas, there are no vapors in the tank to ignite. Sounds dangerous to me.

No, that’s done with water. That way there’s no chance of it catching on fire.

yeah if you’ve ever seen the show myth busters, they recently tested the myth that cell phones can blow up gas stations. incidentally they can’t but the way they tested it was to fill a plexiglass chamber with gas fumes because it’s the fumes, not the liquid that is flammable.

Liquid gasoline will certainly burn, but only the surface that is in contact with air. If you have an open container with gas and light it you will get a very slow burning result. No explosion.

No liquid gasoline will not burn. It is the vapor that burns. The reason that the surface of the liquid gas will burn is because there is vapor there that is what is burning the heat generated by it burning causes more gas to evaporate allowing it to continue burning until all the gas is gone.

Liquid gasoline will burn, just very very poorly. There is nothing chemically wrong about gasoline in its liquid state that will prevent it from reacting with oxygen in the presence of heat to drive it. In practice it does not typically burn as a liquid because the heat of combustion of the currently burning gasoline or ignition source evaporates portions of the liquid. But technically speaking, it will burn as a liquid.

It’s nitpicking but it’s true. Just like coal burns in two modes - by devolatization of the lighter hydrocarbons and hydrocarbon chains that break off from it, and by direct reaction of the char particles of the coal with the oxygen atmosphere around them. That is, the solid turns into a gas which burns, but the solid itself burns as well directly.

BTW dieselmench, I’m not refuting you, because what you said is correct, but just adding that technically speaking from a nitpicking standpoint that only combustion geeks like myself care about, the liquid form will react with oxygen to burn under the right conditions.