Colored flame. Why is the flame of fire first blue and then yellow

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. burner flame gas stove will acquire the same color if sprinkled 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 they contain large amounts of 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.

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 colorful 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. It was also carried out a large number of experiments, 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 hue. 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 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. Selenium gives the flame a blue color. 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.

Light a candle and carefully examine the flame. You will notice that it is not uniform in color. The flame has three zones (Fig.). Dark Zone 1 is at the bottom of the flame. This is the coldest zone compared to the others. The dark zone is bordered by the brightest part of the flame 2. The temperature here is higher than in the dark zone, but the highest temperature is in the upper part of the flame 3 .

To make sure the different flame zones have different temperature, such an experiment can be carried out. Place a splinter (or match) in the flame so that it crosses all three zones. You will see that the splinter is more charred where it hit zones 2 and 3. This means that the flame is hotter there.

To all the answers I will add one more detail, which is used by chemists. There are several zones in the flame structure. The one that is inner, blue, coldest (relative to other zones) is the so-called restorative flame. Those. reduction reactions can be carried out in it (for example, metal oxides). Top part, yellow-red is the hottest zone, which is also called an oxidizing flame. It is in it that the vapors of a substance are oxidized by atmospheric oxygen (unless, of course, we are talking about an ordinary flame). It can carry out the corresponding chemical reactions.

The color of the fire depends on chemical elements which burn out when burning, for example, if you want to see a blue light, then it appears burning natural gas, and is due to carbon monoxide, which gives this shade. Yellow tongues of flame appear when sodium salts break down. 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 tint. 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. Selenium colors the flame blue, and boron colors it blue-green. Red flame will give lithium, strontium and calcium, purple potassium, a yellow-orange hue comes out when sodium is burned.

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The color of the flame depends on its temperature, as well as on the composition of the substance that burns:

4300K ​​- white-yellow, the brightest light;

5000K - cold white;

6000K - white with light blue

8000K - blue-blue - lighting quality is worse.

12000K purple

So, in fact, the hottest flame of a candle is from the bottom, and not from above, as Maxim26ru 325 said, and the temperature at the tip of the flame is higher only due to the presence of gravity on Earth - convection currents arise, as a result of which the heat rushes vertically upwards.

The color of the fire depends directly on the temperature of the flame, and the temperature, in turn, releases a substance that will give a certain color in its spectrum. For example:

Carbohydrate dates are blue;

Bor - Blue-green;

Yellow-orange color is emitted by sodium salts

The green color comes from the release of copper, molybdenum, phosphorus, barium, antimony

Blue is selenium

Red from excretion of lithium and calcium

purple dat potassium

At first, as Alexander Antipov said - yes, the color of the flame is determined by its temperature (if I'm not mistaken, it was proved by Planck). And then the material of what burns accumulates in the flame. Atoms of different elements are able to absorb quanta with a certain energy and emit them back, but with an energy that depends on the nature of the atom. Yellow is the color of sodium in a flame. Sodium is found in any natural organic material. And yellow is able to drown out other colors - this is a feature of human vision.

Well, it depends on what kind of fire. It can be of any color, depending on the burning substance. And such a blue-yellow flame from its heating. The farther the flame is from the burning substance, the more oxygen. And the more oxygen, the hotter the flame and therefore lighter and brighter.

In general, the temperature inside the flame is different and over time it changes (depends on the influx of oxygen and combustible matter). Blue color means that the temperature is very high up to 1400 C, yellow - the temperature is slightly lower than when the blue flame.

Flame color may vary depending on chemical impurities.

In most cases, the flames of a fireplace or campfire are yellow-orange due to the salts contained in the wood. By adding certain chemicals, the color of the flame can be changed to be more appropriate for a special occasion or simply to admire the changing colors. To change the color of a flame, you can add certain chemicals directly to the fire, make paraffin cakes with chemicals, or soak wood in a special chemical solution. For all the enjoyment that the process of creating a colored flame can give you, be sure to take extra care when working with fire and chemicals.

Steps

Choosing the Right Chemicals

Choose the color (or colors) of the flame. Even though you have the option to choose from a whole range of various shades flames, you need to decide which ones are most important to you so you can find the right chemicals. The flame can be made blue, teal, red, pink, green, orange, purple, yellow or white.

Determine the chemicals you need based on the color they produce when burned. To color the flame in desired color, you need to choose the right chemicals. They must be in powder form and not contain chlorates, nitrates or permanganates, which form harmful by-products during combustion.

• To create a blue flame, take copper chloride or calcium chloride.
• To make the flame turquoise, use copper sulfate.
• For a red flame, take strontium chloride.
• To create a pink flame, use lithium chloride.
• To make the flame light green, use borax.
• To get green flames, take alum.
• To create an orange flame, use sodium chloride.
• To create a flame purple take potassium chloride.
• For a yellow flame, use sodium carbonate.
• To create a white flame, take magnesium sulfate.

1. Buy the right chemicals. Some of the flame-staining chemicals are commonly used household chemicals and can be found at the grocery, hardware, or gardening stores. Other chemicals can be purchased from specialty chemicals stores or online.

   • Copper sulfate is used in plumbing to kill tree roots that can damage pipes, so you can look for it in hardware stores.
   • Sodium chloride is a common salt so you can buy it at the grocery store.
   • Potassium chloride is used as a water softener, so you can also look for it in hardware stores.
   • Borax is often used for washing, so you can find it in the department detergents some supermarkets.
   • Magnesium sulfate is found in Epsom salt, which you can ask around in pharmacies.
   • Copper chloride, calcium chloride, lithium chloride, sodium carbonate, and alum should be purchased from chemical stores or online.

Making paraffin cakes

1. Melt the paraffin in a water bath. Place a heatproof bowl over a saucepan of simmering water. Add a few pieces of paraffin to the bowl and let them melt completely.

   • You can use purchased lump or canned paraffin (or wax) or the remains of paraffin from old candles.
   • Do not burn paraffin in an open flame, otherwise you may start a fire.

2. Add the chemical to the paraffin and stir. Once the paraffin has completely melted, remove it from the water bath. Add 1-2 tablespoons (15-30 g) chemical reagent and mix thoroughly until a homogeneous composition is obtained.

   • If you don't want to add the chemicals directly to the paraffin, you can pre-wrap them in used absorbent material and then put the resulting package into the container that you are going to fill with paraffin.

3. Let the paraffin composition cool slightly and pour it into paper cups. After preparing the paraffin mixture with the chemical, let it cool for 5-10 minutes. While the mixture is still liquid, pour it into muffin paper cups to make paraffin tortillas.

   • To make paraffin cakes, you can use both small paper cups and egg cartons.

4. Let the paraffin dry. After the paraffin has been poured into the molds, let it stand until it hardens. It will take about an hour to fully cool down.

   Throw the paraffin cake on the fire. When the paraffin cakes have hardened, remove one of them from the packaging. Toss the tortilla on the hottest part of the fire. As the wax melts, the flame will begin to change color.

   • You can add several paraffin cakes with different chemical additives to the fire at once, just place them in different places.
   • Paraffin cakes work well for campfires and fireplaces.

Wood treatment with chemicals

1. Gather dry and light materials for the fire. Wood-based materials such as wood chips, lumber trimmings, pine cones and brushwood are suitable for you. You can also use rolled up newspapers.

2. Dissolve the chemical in water. Add 450 g of the selected chemical for every 4 liters of water, use for this plastic container. Stir the liquid thoroughly to speed up the dissolution of the chemical. For achievement best results add only one kind of chemical reagent to the water.

   • You can also take a glass container, but avoid using metal containers that can react with chemicals. Be careful not to drop or break used glass containers near a fire or fireplace.
   • Be sure to wear safety goggles, a mask (or respirator), and rubber gloves when preparing the chemical solution.
   • It is best to prepare the solution outdoors, as some types of chemicals can stain the working surface or give off harmful fumes.
3. Be sure to use protective equipment, including goggles and gloves when creating a colored flame.

Warnings

• Handle all chemicals with care and follow the instructions on their packaging. Even completely harmless substances (like table salt) in high concentrations can cause skin irritation and chemical burns.
• Keep hazardous chemicals in sealed plastic or glass containers. Keep children and pets away from them.
• When adding chemicals directly to the fireplace, make sure you have good ventilation first so your home doesn't fill with caustic chemical smoke.
• Fire is not a toy and should never be treated as such. It goes without saying that the fire is dangerous and can quickly get out of control. Be sure to keep a fire extinguisher or a container with enough water handy.

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. 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.

Famous blue the light that can be seen when burning natural gas is due to carbon monoxide, which gives this color. 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 (and table salt, recall, 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. AT 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.