If so, how would one weigh it?
If not, why not?
2006-09-10 00:55:10 · 16 answers · asked by Buzzard 7 in Science & Mathematics ➔ Chemistry
Flames consist of gases that are so hot that they glow. As a simple case, consider a gasoline flame. The inside part of the flame is gasoline vapor (such as octane), the surface (the part that is burning) is gasoline mixed with air and the combustion products water and CO2. Those gases have weight just like other gases. Since they are flowing upwards you can assume that there density is slightly lower than that of the surrounding air, which is typically 1.25 grams per liter. So if you can gouge their volume you have a rough idea of the weight.
Fire as such has weight insofar the flames are heavier than the same gases would be if they were cold. You can compute the thermal energy using the gas law and subsequently convert the energy to mass by dividing by the square of the speed of light (Einstein's formula).
The thermal energy of a one-liter flame with a temperature of 800 degrees Celsius is approximately 200 joule. This is equivalent to 2.2E-12 grams, or 2 trillionths of a gram.
2006-09-10 01:24:37 · answer #1 · answered by helene_thygesen 4 · 2⤊ 5⤋
Sure, fire has a weight. But since fire represents a change in molecular structure (that's why it's on fire, it's being burned) then it's impossible to measure its weight because it is dynamic (i.e. constantly changing).
Furthermore, since it's practically impossible to weigh a hot object (because of convection currents)...weighing an object that is on fire would be even more difficult.
2006-09-10 08:03:42 · answer #2 · answered by The ~Muffin~ Man 6 · 1⤊ 0⤋
You would need to isolate the fire from the fuel, and then the fire would go out. So, yes it has weight, but it would be impossible to actually weigh- you can work it out in theory though.
2006-09-10 08:37:13 · answer #3 · answered by Oracle Of Delphi 4 · 0⤊ 0⤋
Theoretically, yes. The flame is composed of very hot particles which are giving off heat and light. The mass of the particles should be attracted to the earth and should therefore have weight.
Since the flame is a dynamic structure, measuring the mass (to get the weight) would be a very difficult task.
To get a crude approximation of the mass of a flame, one could measure the mass of a candle and then place the candle in a special closed container, which could then be flushed with oxygen gas. If the candle was lighted by using an electric spark and then allowed to burn for a short period of time, it could be extinguished using argon gas (which will not burn) and the gaseous products (Carbon dioxide and water) from the burning could measured in a gas chromatograph.
The oxygen in the products could be calculated and the total carbon and hydrogen from the burning process could be calculated. If this value is then subtracted from the initial mass of the candle and divided by the length of time for the experiment, the mass of the flame per unit time could be calculated.
2006-09-10 07:57:41 · answer #4 · answered by Richard 7 · 8⤊ 1⤋
Fire is gas hot enough to emit light. Thus, one only has to weigh the gas.
2006-09-10 08:30:16 · answer #5 · answered by ag_iitkgp 7 · 1⤊ 0⤋
I guess it does because all it is is hot gas and gas has weight; but I wouldn't want to try to weigh it!
2006-09-11 10:47:23 · answer #6 · answered by Cathy :) 4 · 0⤊ 0⤋
yes, it does
fire is actually hot air that are giving off heat and also colour (as the heat may meake their electrons excited, and when these excited electrins go back, it gives off colour
But practically you can't weigh it, because it has such a small value that buoyancy (archimedes' law) make it unweighable
2006-09-10 10:22:01 · answer #7 · answered by arifin ceper 4 · 0⤊ 0⤋
Everything visible has weight. Suggestion: take a small postal scale outside, light a fire, and put some of it on the scale.
2006-09-10 08:07:42 · answer #8 · answered by Steve 1 · 0⤊ 3⤋
no. Fire is a chemical reaction, the rapid oxidation through combustion of a gas.
2006-09-10 08:01:49 · answer #9 · answered by ceprn 6 · 0⤊ 2⤋
yes fire is having weight but it is negligible.
2006-09-10 08:01:15 · answer #10 · answered by smalleyessharpviews 3 · 1⤊ 1⤋