The expulsion of the green dragon

Burning alcohol with cigarette smoke

Scientific name: Mixture of ethanol vapor and smoke burns in the bottle

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Изгнание зеленого змия - химические опыты

by ПРОСТАЯ НАУКА

HSFC: Chemistry - "Ethanol combustion experiment"

by Havering sfc

Safety

Do not use too much alcohol: ethanol will burn and the bottle can start to melt! Wear eye protection goggles. This is a violent and loud reaction. Keep a safe distance. There is a some fire risk - a fire extinguisher should be ready.

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

Reaction formula

C2H5OH + 3O2 --> 2CO2 + 3H2O

Reagents

  1. Ethanol

Step-by-step instruction

1.Prepare a small plastic bottle. 2.Prepare a sliver or cigarette. 2.Take a smouldering sliver or burning cigarette and fill the bottle with smoke. 3.Add a small amount of ethanol into the bottle. The volume of added ethanol depends on the bottle size. 4.Wait a few minutes for the bottle to fill with ethanol vapor. You can detect it by the specific odour of alcohol from the bottle. 5.Take a burning sliver or a mutch and set fire to ethanol vapor at neck of a bottle. 6.Ethanol fumes burn, smoke helps to visualize the moving of the burning front.

Scientific background

Ethanol is a hightly volatile liquid. Ethanol vapors are highly flammable and burn with a beautiful blue flame. The reaction of combustion of ethanol takes place: C2H5OH + 3O2 --> 2CO2 + 3H2O When we ignite vapors of alcohol in a limited volume, for example, in the bottle, we can observe the movement of the burning front. At the same time we hear a loud shrill whistle. This is due to air entering the bottle, because ethanol vapor and oxygen are burned and air pressure in the bottle falls. The air out of the room quickly drawa into the vessel to equalize the pressure. However, the combustion process is difficult to see during the day, we can see the blue burning front only at night. To conduct this experiment in daytime, we should fill the bottle with smoke. In this case, the movement of smoke shows us the motion of the burning front.

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Published on 10 March 2015

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