This activity should only be carried out by a teacher.
Before performing the experiment please check the risks and safety of Lighter Fluid at the following link:
There is a lot of interesting chemistry in this demonstration. You can discuss density, combustion, miscible and immiscible liquids, polar and nonpolar liquids as well as observation skills.
It is recommended that safety goggles are worn for this demonstration. Before the demonstration, a little lighter fluid is added to the bottom of the flask (less than a ml). The students should be unaware of this.
Drink from a bottle of water. Fill the flask to just below the lip with tap water, don’t let the flask overfill and lose the lighter fluid. Light the liquid on top of the flask. Put the flask on the table. Let the students make observations and figure out what is happening as the lighter fluid is completely burned away.
You'll need an opaque container that viewers can't see is acetone inside. This acetone cannot be the softened acetone that we often find in supermarkets and that is used to remove nail polish, as it is not pure and does not achieve the same results in this trick.
The lower the container and the higher the piece of Styrofoam, the greater the impact.
Start by showing that under the container there is nothing but the table where it is and that it has no hole through which it can get out.
If the table doesn't have a tablecloth so that viewers can see freely under the table, the greater the impact.
Preparation of the Magic Trick:
Water, of course, does not burn. The students should deduce that there is something other than water burning. The immiscible flammable liquid added before the demonstration is less dense than water, floats to the top and is flammable when lit.
Expanded polystyrene articles are manufactured from polystyrene granules that incorporate a blowing agent – a substance which, when heated, gives off a gas. This may be a volatile liquid (such as pentane) or a carbonate. These granules are then steam-heated and the gas from the blowing agent expands to produce a foam plastic. This gas is eventually exchanged with air. Thus the gas in the solid foam is largely air.
The expanded polystyrene does not actually dissolve in the propanone; it merely softens as it absorbs the propanone and allows the air to escape, thereby collapsing the foam. An interesting example of a gas formed not by a chemical process, but by a physical process. The resulting colloidal gel consists of propanone molecules dispersed in a network formed by a tangle of large polystyrene molecules – a similar structure to ordinary jelly in which water molecules are dispersed in a network of protein molecules.
The trick symbolizes the transformation of water into fuel, illustrating the importance of clean and sustainable energy sources. Sustainable energy is essential for achieving SDG 7, which aims to ensure access to affordable, reliable, and sustainable energy for all.
In this trick the audience is made to think that the water is on fire. We can use this trick as an introduction to the discussion about fossil fuels, renewable and non-renewable energies and their impact. With this trick we can ask the question: Can we use only water as fuel? Then we can make a connection with these two SDGs.
Emphasise that the transition to cleaner energy not only benefits the environment but also leads to more resilient and inclusive urban communities, aligning with the principles of SDG 7 and SDG 11.