Liquid light

Two liquids mix together and start to emit a blue light

Scientific name: Chemiluminescence because of oxidation of luminol by hydrogen peroxide

YouTube

Luminol with Hydrogen Peroxide

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Chemiluminescence: Luminol

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Chemiluminescence Reaction using Luminol and Hydrogen Peroxide

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Experience Luminol + H2O2

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Luminol Glow With Hydrogen Peroxide

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Жидкий свет - красивая реакция свечения люминола!

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Elementary Productions: Chemiluminescence of Luminol

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Safety

Wear eye protection and lab gloves. Avoid contact of hydrogen peroxide with skin. Ammonia solution has a strong smell. Work with it in a well ventilated room or in a fume hood.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

C8H7N3O2 + 2OH- + O2 → C8H5NO42- + 2 H2O + N2

Step-by-step instruction

  1. Put 0.2 g of luminol, 12 g of sodium bicarbonate and 0.5 g of copper sulfate into a beaker.
  2. Pour about 500 ml of water and add a few drops of ammonia solution. Luminol dissolves better in an alkaline solution (you may also use sodium hydroxide to alkalize it). Stir to dissolve all compounds.
  3. Prepare the second solution - 5 ml of hydrogen peroxide in 500 ml of water in another beaker.
  4. Mix the same amounts of these solutions to obtain chemiluminescence. You may mix solutions in different ways - in a beaker, in a long tube, make a fountain in a flask with decreased pressure and so on.

Scientific background

In the reaction of luminol oxidation blue light is emitted. This reaction is catalyzed by copper (II) ions and the emission of light increases in presence of these ions. Ferrocyanide ions may also be used for this purpose.

Why does the solution in the flask start glowing?

Luminol is an unusual substance.

Under certain impact conditions, it can donate electrons to other substances – in other words, become oxidized. The process is accompanied by the glow, which can be seen in the dark with the naked eye. This oxidation can only happen if luminol solution includes a certain set of reagents. At the moment when K3[Fe(CN)6] is added to the solution along with the other required components, all the conditions are met for the reaction, and we see a beautiful blue glow.

Now let's examine the roles of each reactant and see how the reaction proceeds. There are four reactants total: luminol itself, red prussiate of potash K3[Fe(CN)6], hydrogen peroxide H2O2, and sodium carbonate Na2CO3.

Danger:
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Published on 13 January 2016

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst