What is Fire?
"Fire" is rapid oxidation of a substance in an exothermic process (combustion). A fire is started when a combustible material combines with sufficient quantities of an oxidizer ( such as oxygen or an oxygen rich compound. Non-oxygen oxidizers can replace oxygen).
The flame is the visible portion of the fire and comprises excited gas/fuel/unburnt particulate matter.
Energy released by the exothermic process is sufficient to excite the electrons in some of constituent atoms and transient intermediates comprising the flame. The excited electrons then fall back to the ground state releasing the absorbed energy as visible light.
Quick Tip: Okay, picture this, an electron walks into a party and drinks a lot. (The brewskis equal energy.)
Now he gets super hammered (i.e goes to a higher energy state) and then later throws up (i.e returns to the ground state). Now if we assume that the electron drank nothing but beer and if we ignore the trace amounts of gastric juice, saliva, and his lunch in his vomit, we can safely say that beer (energy) he egested is equal to the beer (energy) he ingested.
The color of the flame depends primarily on two factors: blackbody radiation and spectral band emission
Typically, in case of complete combustion the excited gas molecules emit pale blue light due to energy transitions (explained above). This is the reason why most gas flames are blue in color.
However, in case of incomplete combustion, the yellow/orange/red color of the flame is due to incandescence of soot particles which glow red hot.
As you may already know that all bodies with temperature above absolute zero (0 K) emit certain electromagnetic radiation corresponding to their temperature.
(Humans emit electromagnetic radiation too, so does your cat and your dog and everything you see around you. The reason we aren't suffused with an incandescent glow is because we are too "Cool" to radiate visible light, rather, we emit infrared radiation..oh yeah!)
Temperature as you know is a measure of the motion of particles constituting matter, and since some of the particles constituting any object will carry charge their movement will lead to the release of electromagnetic radiation i.e light.
The Shape of the Flame
The familiar teardrop shape of a candle flame, here on earth is due to buoyant convection of gas molecules.
The rising hot gases also carry unburnt soot particles to the top of the flame, which make the flame appear yellow.
However, in micro-gravity convection currents are absent and the flame appears somewhat spherical, spreading out in all directions. The flame also appears blue because the soot particles settle down, instead of being carried to the top of the flame by convection currents.
Starting A Fire
The match head of a modern "safety match" is typically composed of potassium chlorate, with a little sulfur and some form of siliceous filler and glue. Some heads contain antimony(III) sulfide to make them burn more vigorously. Safety matches ignite due to the extreme reactivity of phosphorus with the potassium chlorate in the match head.
The main reactant on the striking surface on modern matchboxes is red phosphorous. Safety matches ignite due to the reaction between potassium chlorate and phosphorous. The striking surface also consists of some amount of abrasive material like powdered glass.
DIY Strike Anywhere Matches: Strike anywhere matches are hard to come by (especially here in India) so here's how you can make some at home.
What you need: a) Sand paper
b) Several matchboxes
c) Matchsticks
Using the sandpaper, sand off the red phosphorous from the striking surface of a couple of matchboxes ( you may need about 5-10)
Collect the red phosphorous in a container and mix it with some water. Dip the match heads in the mixture and coat them liberally, after which you can leave them out to dry. Once the water has evaporated, test the matches by striking against any rough surface.
Starting a fire without a match
Combustion, ultimately, is a chemical reaction. Here's a nifty way to start a fire you using chemistry.
Add glycerin to some potassium permanganete, give it about 30 seconds to initiate and Voila, Fire!
What happens here is the glycerin is oxidized extensively by the potassium permanganete and the resulting reaction is highly exothermic and produces a flame.
___________________________
That's all Folks!
The Passive Observer Out!
Confused? Reduction-Oxidation..dafuq?
Do some quick reading
Redox Reactions
"Fire" is rapid oxidation of a substance in an exothermic process (combustion). A fire is started when a combustible material combines with sufficient quantities of an oxidizer ( such as oxygen or an oxygen rich compound. Non-oxygen oxidizers can replace oxygen).
The flame is the visible portion of the fire and comprises excited gas/fuel/unburnt particulate matter.
Energy released by the exothermic process is sufficient to excite the electrons in some of constituent atoms and transient intermediates comprising the flame. The excited electrons then fall back to the ground state releasing the absorbed energy as visible light.
Quick Tip: Okay, picture this, an electron walks into a party and drinks a lot. (The brewskis equal energy.)
Now he gets super hammered (i.e goes to a higher energy state) and then later throws up (i.e returns to the ground state). Now if we assume that the electron drank nothing but beer and if we ignore the trace amounts of gastric juice, saliva, and his lunch in his vomit, we can safely say that beer (energy) he egested is equal to the beer (energy) he ingested.
The color of the flame depends primarily on two factors: blackbody radiation and spectral band emission
Typically, in case of complete combustion the excited gas molecules emit pale blue light due to energy transitions (explained above). This is the reason why most gas flames are blue in color.
However, in case of incomplete combustion, the yellow/orange/red color of the flame is due to incandescence of soot particles which glow red hot.
As you may already know that all bodies with temperature above absolute zero (0 K) emit certain electromagnetic radiation corresponding to their temperature.
(Humans emit electromagnetic radiation too, so does your cat and your dog and everything you see around you. The reason we aren't suffused with an incandescent glow is because we are too "Cool" to radiate visible light, rather, we emit infrared radiation..oh yeah!)
Temperature as you know is a measure of the motion of particles constituting matter, and since some of the particles constituting any object will carry charge their movement will lead to the release of electromagnetic radiation i.e light.
The Shape of the Flame
The familiar teardrop shape of a candle flame, here on earth is due to buoyant convection of gas molecules.The rising hot gases also carry unburnt soot particles to the top of the flame, which make the flame appear yellow.
However, in micro-gravity convection currents are absent and the flame appears somewhat spherical, spreading out in all directions. The flame also appears blue because the soot particles settle down, instead of being carried to the top of the flame by convection currents.
Starting A Fire
The match head of a modern "safety match" is typically composed of potassium chlorate, with a little sulfur and some form of siliceous filler and glue. Some heads contain antimony(III) sulfide to make them burn more vigorously. Safety matches ignite due to the extreme reactivity of phosphorus with the potassium chlorate in the match head.
The main reactant on the striking surface on modern matchboxes is red phosphorous. Safety matches ignite due to the reaction between potassium chlorate and phosphorous. The striking surface also consists of some amount of abrasive material like powdered glass.
DIY Strike Anywhere Matches: Strike anywhere matches are hard to come by (especially here in India) so here's how you can make some at home.
What you need: a) Sand paper
b) Several matchboxes
c) Matchsticks
Using the sandpaper, sand off the red phosphorous from the striking surface of a couple of matchboxes ( you may need about 5-10)
Collect the red phosphorous in a container and mix it with some water. Dip the match heads in the mixture and coat them liberally, after which you can leave them out to dry. Once the water has evaporated, test the matches by striking against any rough surface.
Starting a fire without a match
Combustion, ultimately, is a chemical reaction. Here's a nifty way to start a fire you using chemistry.
Add glycerin to some potassium permanganete, give it about 30 seconds to initiate and Voila, Fire!
What happens here is the glycerin is oxidized extensively by the potassium permanganete and the resulting reaction is highly exothermic and produces a flame.
___________________________
That's all Folks!
The Passive Observer Out!
Confused? Reduction-Oxidation..dafuq?
Do some quick reading
Redox Reactions
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