Blackbody radiation is the emission of light from a hot body; higher the temperature larger the frequency of light emitted light emitted will shift from infrared, red, green, blue towards UV as temperature increases.
This is what the answer on science line points to: more complete the combustion process, more the heat released, and higher the temperature, which makes it look blue. Although the above reasoning of the answer and the physics is correct, this is not typically what happens in gas flames. This is a quantum mechanical phenomena, where the molecule gets into an excited state with the energy supplied by the combustion process and subsequently relaxes to a lower energy state by releasing the extra energy in the form of light.
The color of the light emitted in this process is characteristic of the molecule excited. Both, blackbody radiation and molecular excitation should be discussed in the context of color of the flame.
Orange flame is due to blackbody radiation coming out from an incomplete combustion or slightly cooler area, where the released energy is not enough to excite the molecules. When the combustion process is complete and produces enough heat to excite molecules, the molecular excitation produces a distinct bluish-green spectrum.
A simple and beautiful experiment to see molecular excitation in play is to hold a salt in flame and see the color emitted. This is often used to identify a salt, since the color is characteristic of the molecule. Calcium salts emit brick-red color, Copper compounds emit greenish blue flame.
Here is a youtube link: click here to watch. Experiment suggested by a reader: I just thought of an experiment to suggest to your audience. This can be carried out in an undergraduate lab. The air to gas ratio for LPG gases is higher. The air to gas ratio for propane gas is approximately The air to gas ratio for butane gas is approximately To achieve this difference, LPG is typically provided in a smaller quantity but at a higher pressure, drawing more oxygen with it into the combustion process, giving LPG a higher air to gas ratio than for natural gas.
A yellow or red flames on gas stove is dangerous, as it is indicative of incomplete combustion and carbon monoxide CO generation. A gas cooker yellow flame is a dangerous safety problem, if it occurs with an indoor appliance like a gas stove.
You could also be wasting gas. A blue flame means complete combustion is taking place. A key warning sign that you require gas appliance servicing are yellow or red flames or a gas flame colour with a yellow burning tip. The exceptions to this are gas fireplaces and gas log fires that are designed to have a yellow or red flames. Burners blocked with dirt can result in improper combustion, leading to soot build up inside the appliance.
Flames in a gas oven should burn with a blue flame colour, meaning complete combustion, as with other gas appliances.
Blue flame in gas oven applies to the flame color of propane or natural gas cooktops, as well. The LPG propane is a blue flame because complete combustion creates enough energy to excite and ionize the gas molecules in the flame.
The exception is a gas fireplace having yellow or red flames, for a more realistic look. Burning wood has yellow-red flames due to incandescence of very fine soot particles that are produced in the flame.
All gas appliances, domestic and industrial, produce water vapour, Carbon Dioxide and heat, and usually very small amounts of Carbon Monoxide. If installed and maintained correctly, the operation of the gas appliance provides quick and efficient heating, cooking, hot water and more, and the products of combustion do not create any hazardous situations.
If an appliance is not correctly installed and maintained or has been modified, the products of combustion might change, and become hazardous to the people around the appliance. Something as simple as a ventilation change getting fresh air to the appliance to sustain complete combustion may cause a gas appliance to malfunction, and create a hazardous situation for the people around.
Sooty smoke, yellow or red flames or poor performance are indicators, but sometimes no indicators are obvious. If Carbon Monoxide CO is produced and escapes the appliance into the surrounding air, it will not be obvious no smell and no taste but will be very dangerous.
It is essential that gas appliances are correctly installed and serviced every two years, to maintain good combustion and safe, efficient operation.
If you experience any signs of carbon monoxide poisoning while operating your indoor gas appliance, you should stop using it until it is serviced by your gas fitter. With complete combustion you get the maximum heat output from your gas and use less gas to generate heat with whatever appliance you are using. Keep an eye on your gas appliances and have them serviced, as needed, to keep them operating properly and safely. Please Email us at: [email protected]. The information in this article is derived from various sources and is believed to be correct at the time of publication.
However, the information may not be error free and may not be applicable in all circumstances. Blue flame temperatures assume complete combustion. Flame Color. Temperature Chart. LPG Propane. Blue Flame. There's one other color you may have seen appear in flames on a regular basis: blue.
For example, if you have a gas stove at home or have ever seen one operate, you know that the natural gas flames are mainly blue. Likewise, the portion of a flame closest to a candle or a piece of wood might also have blue mixed in with the white. The color blue indicates a temperature even hotter than white. Blue flames have more oxygen and get hotter because gases burn hotter than organic materials, such as wood. When natural gas is ignited in a stove burner, the gases quickly burn at a very high temperature , yielding mainly blue flames.
While variances in temperature account for most of the colors visible in flames, the chemical composition of the fuel can also be a factor. For example, common fossil fuels, such as natural gas and oil , are made up mostly of hydrocarbon compounds, which emit light in the blue spectrum.
If other chemical elements are present, they may give off their own unique wavelengths of light when burned. For example, the element lithium will produce a pink flame , while the element tungsten will produce a green flame. We hope you enjoyed today's colorful Wonder of the Day! Be sure to grab a friend or family member to help you check out the following activities:. Thanks, Tariya!! ANd you're right, we should always be careful around fire.
That's awesome, Zac! Hi, Ahmad! Thanks for sharing your thoughts about this Wonder question! You're right that the chemical reaction does impact the color. We posted the Wonder Sources if you are interested in learning more! Hi, Denzel! S'mores are yummy!
Hello, Quinn Haper! There is one showing white fire. Welcome, Dash Classroom! I'm from Australia so I use the metric system GMc you could always look up on the internet for the metric conversions. Thanks for your feedback, Gmc! We appreciate you sharing your thoughts with us. Welcome, cathy! You make two great connections to the color of fire. Great thinking, Saige Stevenson! Why do you think this is? We are undergoing some spring clearing site maintenance and need to temporarily disable the commenting feature.
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Tags: See All Tags burn , chemistry , color , combustion , fire , flame , fossil fuel , gas , heat , hydrocarbon , lithium , organic , oxidant , oxygen , reaction , science , spectrum , temperature , tungsten , wavelength. Wonder What's Next? Be sure to grab a friend or family member to help you check out the following activities: Do you have a gas stove at home?
If not, find a friend or family member who has one.
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