Screaming jelly babies





Screaming jelly babies is a classic chemistry demonstration which is
practiced in schools all over the UK {and perhaps the rest of the world?}It
is often used at open evenings to demonstrate just how much fun secondary
school science can be. The following text gives an explanation of how to
perform the experiment. This should only be done by an experienced
chemist/chemistry teacher.

This demonstration nicely shows just how much energy there is in a "jelly
baby". Potassium chlorate is a very strong oxidizing agent that oxidizes the
sugar in the jelly baby all at once.

Safety

  1. Make sure test tube is squeaky clean. Any trace of an oxidizable
     material can cause an explosion
  2. Surround the apparatus with safety screens
  3. Ensure the pupils / audience are seated several metres away and that
     they are wearing eye protection

You will need

   * Jelly babies
   * Large test tubes
   * Clamp Stand {retort stand}
   * Potassium chlorate
   * Tongs
   * Access to a fume cupboard
   * Bunsen burner
   * Safety goggles
   * Fire resistant surface

Method

  1. Put 10mg potassium chlorate in large test tube .
  2. Clamp the tube in a clamp stand at approx. 60 ¡ (just off the vertical)
     then melt the powder in a fume cupboard with a bunsen burner. Wear a
     full face visor.
  3. Turn the bunsen off, then, using tongs and wearing heat resistant
     gloves, drop in the jelly baby.

Results

If all goes well the jelly baby will burst into flames and make a very nice
screaming sound as it burns to death! A smell of 'candy floss' will also
steal its way around the room.