Description:

A small amount of methanol is ignited in order to expel a small rubber stopper.  


 Watch Video: 

 


Other Demos of Interest:

How to Make a Water Rocket How to Make a Vortex Cannon How to Make an Air Cannon

 


Possible Incorporated Topics:

  • projectile motion
  • pressure 

 


Theory:

Methanol is extremely flammable and will light quickly when ignited. When the tesla coil lends a spark to the gap inside the sealed rubber tube, the spark ignites the ethanol.

The methanol ignites in the air and undergoes the following chemical reaction:

 

This reaction increases the temperature of the gas in the tube, as well as number of moles. Before the reaction, there are 5 moles of gas, while there are 6 moles after the reaction. The reaction is exothermic and so releases energy, thus generating heat. 

This increases the pressure in the tube such that it blows the top off, firing it far across the room.  

This is the same principle behind combustion in a car’s engine.

 


Apparatus:

  • Strong Rubber Build with Spark Electrodes
  • Tesla Coil
  • Rubber Stopper
  • Methanol 
  • Table Clamps

Procedure:

  • Squirt a small amount of methanol into the rubber bulb and swirl it around for a couple of seconds.  
  • Pour the excess liquid methanol out and discard safely.  
  • Plug the top of the bulb with the rubber stopper and mount it safely in the clamp.  
  • Ensure that the bulb is pointed away from anything that could be damaged by the expulsion of the stopper.  
  • Wearing eye protection, place the activated Tesla coil near the electrode.  
  • The ensuing spark will ignite the methanol vapour, causing a small explosion that will shoot the stopper across the room.

 


SAFETY

You must wear safety glasses while performing this experiment.  Please ensure all safety protocols are followed.  This experiment should not be performed alone.