Canister Poppers

Exploding

 

 

 

Category - Chemicals & Reactions

Key Idea - Acids & Bases

 

Purpose - An excellent demonstration of the reaction between a carbonate and an acid.  Can also be used to show the fact that gases require more space than solids or liquids.

The materials required for canister poppers.  Note the Aluminium foil boat in the foreground loaded with bicarb soda.
Nature -  Practical
Materials -  Plastic film canisters with lids, vinegar, bi-carbonate of soda, aluminium foil
Method - 
  1. One third fill the film canister with vinegar
  1. Use about a 3cm square piece of aluminium foil to make a small boat that just fits into the canister.
  2. Load the canister with bicarb soda and carefully float the boat on the vinegar
  3. Carefully put the lid on the canister
  4. Keeping your head away from the lid, give the canister a quick shake and put it down.  The lid should pop off from the canister and fly into the air.
  5. A variation is to just turn the canister over onto it's lid.  In this case the actual canister pops off into the air.

 

Safety - General concerns of using a weak acid, especially avoiding contact with eyes. Fast moving canister lids can be a minor hazard as projectiles.
Explanation - The acidic vinegar and the bi-carb react to produce carbon dioxide gas.  This gas is unable to escape and so builds up until it is able to push the lid off the canister with significant pressure.  The reaction of vinegar with bicarb soda is shown at above
Notes - This is probably a prac best done outside on boards as it is not uncommon for the lids and some vinegar to hit the ceiling.  Some things to try with a class include predicting the effect of variables amount of bicarb soda and vinegar used or the type of film canister used.