What determines the color of fire? Fire temperature of different flame sources.

18.12.2017 08:06 772

Why does fire happen different colors?

Fire has always been a source of light and heat for people. Its bewitching glow has attracted people with its mystery since ancient times. Many peoples performed various rituals by the fire. It is known that fire is a combination of hot gases that are released as a result of heating some combustible materials, such as wood.

Sitting by the fire, and watching its bright flame, it seems that the fire comes in only two colors: red and yellow. But in fact it is. Fire can be of different colors. Why it happens?

The color of the flame depends on the composition of the burning material. During the combustion process, chemical reactions giving flame different colors. You guys probably noticed that when you turn on gas stove the fire on the burners glows blue color. This is because the gas decomposes into hydrogen and carbon during combustion. This creates carbon dioxide which gives the flame a blue color.

If the flame is shining in green, it means that copper or phosphorus is present in the burning material. The yellow color of fire occurs when salt is burned. When burning wood, the flame will also have yellow tint, since salt is also present in the tree.

Also, the fire may have a red tint if lithium or potassium is present in the composition of the burning material.

Here we have found out the answer to our question. But it should be remembered, guys, that fire is a great danger for a person. Therefore, it is strictly forbidden to use fire without the presence of adults.

For many centuries, fire has played a very important role in human life. Without it, it is almost impossible to imagine our existence. It is used in all areas of industry, as well as for cooking, warming the house and the development of technological progress.

Fire first appeared in the early Paleolithic era. Initially, it was used in the fight against various insects and attacks of wild animals, and also gave light and heat. And only then the flame of fire was used in cooking, making dishes and tools. So the fire entered our lives and became " indispensable assistant» person.

Many of us have noticed that the flame can be different in its color scheme, but not many people know why the fire element has a motley color. As a rule, the color scheme of fire depends on what chemical substance burns in it. Through the action of high temperature, all chemical atoms are released, thus giving color to the fire. A large number of experiments were also carried out, which will be described in this article a little later, in order to understand how these substances affect the color of the frying pan.

Since ancient times, scientists have made efforts to understand what chemical substances burn in a flame, depending on what color the fire took on.

All of us at home when cooking can watch the light with blue tint. This is predetermined by easily combustible carbon and carbon monoxide, which gives the light this blue tint. Sodium salts, which are endowed with wood, give the fire a yellow-orange hue, which burns an ordinary fire or matches. If sprinkled on the stove burner regular salt, then you can get the same color. Green color copper gives fire. At a very high concentration of copper, the light has a very bright shade of green, which is virtually identical to colorless white. This can be observed if you sprinkle the burner with copper shavings.

Experiments were also carried out with an ordinary gas burner and various minerals in order to establish their constituent chemicals. To do this, the mineral is carefully taken with tweezers and brought to the fire. And, by the shade that the fire took on, one can draw conclusions about the various chemical additives that are present in the element. Minerals such as copper, barium, phosphorus, molybdenum give a green tint, while boron and antimony give a blue-green color. Also in blue color flame attaches selenium. A red flame is obtained by adding lithium, strontium and calcium, a violet one is obtained by burning potassium, and a yellow-orange color gives sodium.

To study various minerals and determine their composition, a Bunsen burner, invented in the 19th century by Bunsen, is used, which gives a colorless flame color that does not interfere with the experiment.

It was Bunsen who became the founder of the methodology for determining chemical composition substances according to color palette flame. Of course, before him there were attempts to conduct such experiments, but such experiments were unsuccessful, since there was no burner. He introduced various chemical components into the fire element of the burner on a wire made of platinum, because platinum does not affect the color of the fire in any way and does not give it any shade.

At first glance, it may seem that there is no need for any complex chemical research; you bring the component to the fire and you can instantly see its composition. However, not all so simple. In nature, substances in their pure form are very rare. As a rule, they include a considerable set of different impurities that can change color.

Therefore, with the help characteristic properties molecules and atoms emit light of a certain colors- a method was created for determining the chemical composition of substances. This method of determination is called spectral analysis. Scientists study the spectrum that emits a substance. For example, during combustion, it is compared with the spectra of known components, and thus its chemical composition is established.

Description:

Wetting a copper plate in hydrochloric acid and bringing it to the flame of a burner, we notice an interesting effect - the coloring of the flame. The fire shimmers with beautiful blue-green hues. The spectacle is quite impressive and bewitching.

Copper gives the flame a green tint. With a high content of copper in the combustible substance, the flame would have a bright green color. Copper oxides give an emerald green color. For example, as can be seen from the video, when copper is wetted with hydrochloric acid, the flame turns blue with a greenish tint. And the calcined copper-containing compounds, moistened with acid, color the flame in an azure blue color.

For reference: Barium, molybdenum, phosphorus, antimony also give green color and its shades to fire.

Explanation:

Why is the flame visible? Or what determines its brightness?

Some flames are almost invisible, while others, on the contrary, shine very brightly. For example, hydrogen burns with an almost completely colorless flame; the flame of pure alcohol also shines very faintly, and a candle and a kerosene lamp burn with a bright luminous flame.

The fact is that the greater or lesser brightness of any flame depends on the presence of incandescent solid particles in it.

The fuel contains more or less carbon. Particles of carbon, before burning, glow, - that's why the flame gas burner, kerosene lamp and the candles shine - because it is illuminated by incandescent carbon particles.

Thus, it is possible to make a non-luminous or weakly luminous flame bright by enriching it with carbon or by heating non-combustible substances with it.

How to get colorful flames?

To obtain a colored flame, not carbon is added to the burning substance, but metal salts that color the flame in one color or another.

The standard method for coloring a faintly luminous gas flame is to introduce metal compounds into it in the form of volatile salts - usually nitrates (salts of nitric acid) or chlorides (salts of hydrochloric acid):

yellow- sodium salts,

red - salts of strontium, calcium,

green - cesium salts (or boron, in the form of boron ethyl or boron methyl ether),

blue - copper salts (in the form of chloride).

IN blue colors the flame with selenium, and blue-green with boron.

This ability of burning metals and their volatile salts to give a certain color to a colorless flame is used to obtain colored fires (for example, in pyrotechnics).

What determines the color of the flame (scientific language)

The color of a fire is determined by the temperature of the flame and the chemicals it burns. Heat flame allows the atoms to jump for a while to a higher energy state. When atoms return to their original state, they emit light with a certain wavelength. It corresponds to the structure of the electron shells of a given element.

It is easy to guess that the hue of the flame is determined by the chemicals that burn in it, in the event that exposure to high temperature releases individual atoms of the combustible substances, coloring the fire. To determine the effect of substances on the color of fire, various experiments were carried out, which we will discuss below.

Since ancient times, alchemists and scientists have tried to find out what substances burn, depending on the color that the flame acquired.

Flame geysers and plates available in all houses and apartments, has a blue tint. Such a shade during combustion gives carbon, carbon monoxide. The yellow-orange color of the fire flame, which is bred in the forest, or household matches, is due to the high content of sodium salts in natural wood. Largely due to this - red. The flame of a gas stove burner will acquire the same color if you sprinkle it with ordinary table salt. When burning copper, the flame will be green. I think you have noticed that with a long wear, rings or chains made of ordinary copper, not covered protective composition skin turns green. The same thing happens during the combustion process. If the copper content is high, there is a very bright green fire, almost identical to white. This can be seen if you pour on gas burner copper shavings.

Many experiments have been carried out involving an ordinary gas burner and various minerals. Thus, their composition was determined. You need to take the mineral with tweezers and place it in the flame. The color that the fire takes on can indicate the various impurities present in the element. The flame of green color and its shades indicates the presence of copper, barium, molybdenum, antimony, phosphorus. Boron gives a blue-green color. Selenium gives the flame a blue tint. The flame turns red in the presence of strontium, lithium and calcium, purple - potassium. The yellow-orange color is obtained during the combustion of sodium.

Studies of minerals to determine their composition are carried out using a Bunsen burner. The color of its flame is even and colorless; it does not interfere with the course of the experiment. Bunsen invented the burner in the middle of the 19th century.

He came up with a method that allows you to determine the composition of a substance by the shade of the flame. Scientists tried to conduct similar experiments before him, but they did not have a Bunsen burner, the colorless flame of which did not interfere with the course of the experiment. He placed various elements on a wire of platinum in the fire of the burner, since when this metal is added, the flame does not color. At first glance, the method seems good, you can do without the laborious chemical analysis. It is enough just to bring the element to the fire and see what it consists of. But substances in their pure form can be found in nature extremely rarely. Usually in them in large numbers contains various impurities that change the color of the flame.

Bunsen tried to highlight colors and shades various methods. For example, using colored glasses. Let's say if you look through the blue glass, you won't see yellow, in which the fire is painted when burning the most common sodium salts. Then the lilac or crimson hue of the desired element becomes discernible. But even such tricks led to the correct determination of the composition of a complex mineral in very rare cases. More than this technology could not achieve.

Nowadays, such a torch is used only for soldering.

Under laboratory conditions, a colorless fire can be achieved, which can only be determined by the fluctuation of air in the combustion area. Household fire is always "colored". The color of a fire is determined mainly by the temperature of the flame and the chemicals it burns. The high temperature of the flame allows the atoms to jump to a higher energy state for a while. When atoms return to their original state, they emit light of a certain wavelength. It corresponds to the structure of the electron shells of a given element.

Famous blue a flame that can be seen when burning natural gas, due to carbon monoxide, which gives this shade. Carbon monoxide, whose molecule consists of one oxygen atom and one carbon atom, is a by-product of burning natural gas.

Try sprinkling a little salt on the burner of a gas stove - yellow tongues will appear in the flame. Such yellow-orange flame give sodium salts salt, remember, this is sodium chloride). Wood is rich in such salts, so an ordinary forest fire or household matches burn with a yellow flame.

Copper attached to the flame green shade. With a high content of copper in the combustible substance, the flame has a bright green color, almost identical to white.

Barium, molybdenum, phosphorus, antimony also give green color and its shades to fire. IN blue selenium colors the flame, and in blue-green- boron. Lithium, strontium and calcium will give a red flame, potassium will give a violet one, and sodium will burn a yellow-orange hue.

Flame temperature during combustion of certain substances:

Do you know...

Due to the property of atoms and molecules to emit light of a certain color, a method was developed for determining the composition of substances, which is called spectral analysis. Scientists study the spectrum that a substance emits, for example, during combustion, compare it with the spectra of known elements, and thus determine its composition.