“Colored Flame” experiment
Ноw to turn a flame different colors
We're all used to flame being yellowy-orange. But can we turn a flame different colors? For example, blue, red or green? In our experiment, we will show you how to turn flame bright colors with salts.
Reagents and equipment:
- aluminum cups;
- sodium chloride (10 g);
- copper(II) chloride dihydrate (10 g);
- strontium chloride (10 g);
- barium nitrate (10 g);
- lithium bromide (10 g);
- ethyl alcohol (96%);
Sprinkle 10 g of salts into the aluminum cups (for example the kind used as candle holders). Then add 5-10 g of 96% ethyl alcohol, light it. After a while the flame of the alcohol will turn different colors.
Many ions of metals and non-metals turn flame different colors. This is because when heated, atoms move to an excited (or unstable) state. When they return to their original (stable) state, the excess of accumulated energy is released in the form of light of a certain wavelength, which is characterized by the color we observe. This amazing property is used to make colored fireworks, in qualitative analysis of minerals, as a certain ion corresponds to a certain wavelength of color emitted. For example, sodium ions give a yellow color, which we can observe when heating soup on a gas stove. Potassium ions give a dark pink color, which we can observe when preparing a recipe which uses wine – wine contains potassium tartrate, potassium salt and tartaric acid. Boric acid gives a green color because of the presence of boron. Barium salt gives a yellowy-green color, copper salts — green, calcium salts — brick-red, strontium — a crimson color, etc.
Wear protective gloves and glasses and work in a well-ventilated room. Observe safety rules when working with fire and flammable liquids.
Warning! Don’t try to repeat this experiment without a professional supervision!