Colored fire

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A campfire burning with blue and green flame colorants Colored Campfire - panoramio.jpg
A campfire burning with blue and green flame colorants
Different colors of natural flame from a bunsen burner, without additives Bunsen burner flame types.jpg
Different colors of natural flame from a bunsen burner, without additives

Colored fire is a common pyrotechnic effect used in stage productions, fireworks and by fire performers the world over. Generally, the color of a flame may be red, orange, blue, yellow, or white, and is dominated by blackbody radiation from soot and steam. When additional chemicals are added to the fuel burning, their atomic emission spectra can affect the frequencies of visible light radiation emitted - in other words, the flame appears in a different color dependent upon the chemical additives. Flame coloring is also a good way to demonstrate how fire changes when subjected to heat and how they also change the matter around them. [1] [2]

Contents

To color their flames, pyrotechnicians will generally use metal salts. Specific combinations of fuels and co-solvents are required in order to dissolve the necessary chemicals. Color enhancers (usually chlorine donors) are frequently added too, the most common of which is polyvinyl chloride. A practical use of colored fire is the flame test, where metal cations are tested by placing the sample in a flame and analyzing the color produced. [3] [4]

Flame colorants

ColorChemicalImage
Red Strontium chloride or strontium nitrate FlammenfarbungSr.png
Orange Calcium chloride FlammenfarbungCa.png
Yellow-green Barium chloride
Orange-yellow Sodium chloride (table salt) Flametest--Na.swn.jpg
Apple green Borax (sodium borate) FlammenfarbungB.png
Green Copper(II) sulfate and boric acid Flametest--Cu.swn.jpg
Blue Copper(I) chloride and butane Flametest--.swn.jpg
Violet3 parts potassium sulfate, 1 part potassium nitrate (saltpeter)
Blue/light violet Potassium chloride FlammenfarbungK.png
White/Yellow Nitromethane [5] Nitromethaneflame.jpg

Emitted colors depend on the electronic configuration of the elements involved. Heat energy from the flame excites electrons to a higher quantum level, and the atoms emit characteristic colors (photons with energies corresponding to the visible spectrum) as they return to lower energy levels [6]

Campfire colorants

Flame colorants are becoming popular while camping. Scouts [ citation needed ] and other outdoor enthusiasts have placed sections of copper pipe with holes drilled throughout and stuffed with garden hose onto campfires to create a variety of flame colors. An easier method of coloring campfires has been fueled by commercial products. These packages of flame colorants are tossed onto a campfire or into a fireplace to produce effects.

Although these chemicals are very effective at imparting their color into an already existing flame, these substances are not flammable alone. To produce a powder or solid that, when lit, produces a colored flame, the necessary steps are more complex. To get a powder to burn satisfactorily, both a fuel and oxidizer will mostly be needed. Common oxidizers include. [7]

Many of these oxidizers also produce a colored flame by themselves. Some of them - as well as the main colorants - are severely toxic and therefore environmentally damaging.

Related Research Articles

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An explosive is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances.

<span class="mw-page-title-main">Oxidizing agent</span> Chemical compound used to oxidize another substance in a chemical reaction

An oxidizing agent is a substance in a redox chemical reaction that gains or "accepts"/"receives" an electron from a reducing agent. In other words, an oxidizer is any substance that oxidizes another substance. The oxidation state, which describes the degree of loss of electrons, of the oxidizer decreases while that of the reductant increases; this is expressed by saying that oxidizers "undergo reduction" and "are reduced" while reducers "undergo oxidation" and "are oxidized". Common oxidizing agents are oxygen, hydrogen peroxide, and the halogens.

<span class="mw-page-title-main">Flame</span> Visible, gaseous part of a fire

A flame is the visible, gaseous part of a fire. It is caused by a highly exothermic chemical reaction taking place in a thin zone. When flames are hot enough to have ionized gaseous components of sufficient density they are then considered plasma.

<span class="mw-page-title-main">Potassium chlorate</span> Chemical compound

Potassium chlorate is a compound containing potassium, chlorine and oxygen, with the molecular formula KClO3. In its pure form, it is a white crystalline substance. After sodium chlorate, it is the second most common chlorate in industrial use. It is a strong oxidizing agent and its most important application is in safety matches. In other applications it is mostly obsolete and has been replaced by safer alternatives in recent decades. It has been used

<span class="mw-page-title-main">Roman candle (firework)</span> Firework that ejects stars or exploding shells

A Roman candle is a traditional type of firework that ejects one or more stars or exploding shells. Roman candles come in a variety of sizes, from 6 mm (0.24 in) diameter for consumers, up to 8 cm (3.1 in) diameter in professional fireworks displays.

<span class="mw-page-title-main">Chlorate</span> Anion and term for chemical compounds containing it

Chlorate is the common name of the ClO
3
anion, whose chlorine atom is in the +5 oxidation state. The term can also refer to chemical compounds containing this anion, with chlorates being the salts of chloric acid. Other oxyanions of chlorine can be named "chlorate" followed by a Roman numeral in parentheses denoting the oxidation state of chlorine: e.g., the ClO
4
ion commonly called perchlorate can also be called chlorate(VII).

<span class="mw-page-title-main">Perchlorate</span> Ion, and compounds containing the ion

A perchlorate is a chemical compound containing the perchlorate ion, ClO4-, the conjugate base of perchloric acid (ionic perchlorate). As counterions, there can be metal cations, quaternary ammonium cations or other ions, for example, nitronium cation (NO2+).

<span class="mw-page-title-main">Sparkler</span> Type of pyrotechnic device

A sparkler is a type of hand-held firework that burns slowly while emitting bright, colored sparks.

<span class="mw-page-title-main">Potassium perchlorate</span> Chemical compound

Potassium perchlorate is the inorganic salt with the chemical formula KClO4. Like other perchlorates, this salt is a strong oxidizer although it usually reacts very slowly with organic substances. This, usually obtained as a colorless, crystalline solid, is a common oxidizer used in fireworks, ammunition percussion caps, explosive primers, and is used variously in propellants, flash compositions, stars, and sparklers. It has been used as a solid rocket propellant, although in that application it has mostly been replaced by the higher performance ammonium perchlorate.

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Flash powder is a pyrotechnic composition, a mixture of oxidizer and metallic fuel, which burns quickly (deflagrates) and produces a loud noise regardless of confinement. It is widely used in theatrical pyrotechnics and fireworks and was once used for flashes in photography.

A pyrotechnic colorant is a chemical compound which causes a flame to burn with a particular color. These are used to create the colors in pyrotechnic compositions like fireworks and colored fires. The color-producing species are usually created from other chemicals during the reaction. Metal salts are commonly used; elemental metals are used rarely.

A pyrotechnic composition is a substance or mixture of substances designed to produce an effect by heat, light, sound, gas/smoke or a combination of these, as a result of non-detonative self-sustaining exothermic chemical reactions. Pyrotechnic substances do not rely on oxygen from external sources to sustain the reaction.

<span class="mw-page-title-main">Barium oxalate</span> Chemical compound

Barium oxalate (BaC2O4), a barium salt of oxalic acid, is a white odorless powder that is sometimes used as a green pyrotechnic colorant generally in specialized pyrotechnic compositions containing magnesium metal powder. Flame color is rich and vivid without additional chlorine donors. Such compositions burn rate is satisfied without commonly used oxidizers as nitrates, chlorates and perchlorates.

Calcium chlorate is the calcium salt of chloric acid, with the chemical formula Ca(ClO3)2. Like other chlorates, it is a strong oxidizer.

<span class="mw-page-title-main">Barium chlorate</span> Chemical compound

Barium chlorate, Ba(ClO3)2, is the barium salt of chloric acid. It is a white crystalline solid, and like all soluble barium compounds, irritant and toxic. It is sometimes used in pyrotechnics to produce a green color. It also finds use in the production of chloric acid.

<span class="mw-page-title-main">Flare (countermeasure)</span> Aerial countermeasure against heat-seeking missiles

A flare or decoy flare is an aerial infrared countermeasure used by a plane or helicopter to counter an infrared homing ("heat-seeking") surface-to-air missile or air-to-air missile. Flares are commonly composed of a pyrotechnic composition based on magnesium or another hot-burning metal, with burning temperature equal to or hotter than engine exhaust. The aim is to make the infrared-guided missile seek out the heat signature from the flare rather than the aircraft's engines.

In pyrotechnics, a pyrotechnic initiator is a device containing a pyrotechnic composition used primarily to ignite other, more difficult-to-ignite materials, such as thermites, gas generators, and solid-fuel rockets. The name is often used also for the compositions themselves.

A smoke composition is a pyrotechnic composition designed primarily to generate smoke. Smoke compositions are used as obscurants or for generation of signaling smokes. Some are used as a payload of smoke bombs and smoke grenades.

Alkali metal nitrates are chemical compounds consisting of an alkali metal and the nitrate ion. Only two are of major commercial value, the sodium and potassium salts. They are white, water-soluble salts with melting points ranging from 255 °C to 414 °C on a relatively narrow span of 159 °C

An environmentally friendly red-light flare was a pyrotechnic (firework) flare which used lithium-based formulations that emitted red light. A flare is used for signaling, illumination, or defensive countermeasures in civilian or military applications. It is based on a non-hygroscopic dilithium nitrogen-rich salt that served as an oxidizer and red colorant. The U.S. Army Research Laboratory and the Ludwig Maximilian Institution were credited as the research facilities for developing this product announced in January 2018.

References

  1. "Blackbody Radiation". Archived from the original on 2014-01-08.
  2. "Atomic Absorption and Emission Spectra". Archived from the original on 2014-03-26. Retrieved 2014-04-01.
  3. "flame tests". Chemguide.co.uk. Retrieved 2017-08-02.
  4. "Pyrotechnic Chemicals - Chlorine Donors". Skylighter, Inc. Retrieved 2017-08-02.
  5. This flame looks fake but is real (nitromethane) – YouTube
  6. "Flame Colors as Chemical Indicators". Archived from the original on 2014-10-07. Retrieved 2014-04-01.
  7. "Colored Fire Flames". Campfiredude.com. Retrieved 2017-08-02.