Design an experiment to show that candle wax does not burn with complete combustion

candle-wax

#1

design an experiment to show that candle wax does not burn with complete combustion

Answer:

So a simple way of determining complete combustion is the presence of soot or some sort of remaining residue after combustion. What this means is that some of the compounds did not get completely converted into water or carbon dioxide. A way to do this would be to take a chunk of candle wax and burn it with a torch of some kind. The wax will discolor and there will be a black, sooty kind of material (if you have ever burned a candle you’ll probably notice some black material around the container).

Therefore, an experiment to show that candle wax does not burn with complete combustion could go something like so:

  1. Obtain a sample of candle wax.
  2. Place candle wax in fire-proof container.
  3. Using a torch (propane, butane, etc.) apply heat to the wax.
  4. Once all of the wax appears to have burned away, look for the presence of black material- this is what remains of the wax, the incomplete combustion products.

You could also devise a much more complicated experiment wherein you have a sample of wax in a container that is attached solution containing calcium oxide (CaO). The carbon dioxide and water would react with the calcium oxide and form insoluble calcium carbonate and a solution calcium hydroxide (Note: this reaction would be carried out under extremely high temperatures, involve caustic compounds, and be VERY dangerous- but should yield a similar finding). The wax would be heated by some sort of extremely hot element so as to get it to ignite and the gases emitted would be pushed into the calcium oxide forming the aforementioned products confirming the presence of water and carbon dioxide. However, there should be again some black material left over inside the vessel where the wax was heated, this would show again that there was incomplete combustion.