Banging Soap Bubbles
Chemistry Week is nearly up on us! It’s a great opportunity to help inspire young Chemists and show how exciting the world of chemistry really is. Why not get your chemistry week off to a bang, by showing your students the exploding soap bubbles experiment?
This experiment is one of the most visual and spectacular experiments that you can carry out in a class room! Methane added to the soap bubbles pop and explode to give your class a real insight to gasses and how they work when exposed to different conditions.
You will need:
- oxygen cylinder
- methane - from gas tap
- rubber tubing
- metre rule
- wooden splints
- tape (to tape splints to the metre rule)
- Gratnells Tray or plastic washing-up bowl
- washing up liquid
- ear defenders
- eye protection
- warm water
Procedure:
1) Fill half a Gratnells with hot water and then add approx 50ml of washing up liquid and gently mix.
2) Connect a length of rubber tubing to a gas tap and hold the other end in the soapy water. Open the gas tap just enough to produce a slow stream of small bubbles, they should collect on the surface.
3) Once this Is done at the oxygen, at roughly twice the rate of the methane
4) Using your hand, scoop out some the bubbles with a combined volume no greater than a tennis ball, and place on lab bench. Using a burning lit splint taped to a metre rule, and held at arm’s length, ignite the bubbles.
Special tips:
- As always, practice makes perfect with this experiment! Practice before this is done live in front of your class!
- start with bubbles of pure methane to illustrate the slow combustion of methane in the limited supply of oxygen from the surrounding air
- Always make sure you have the appropriate safety equipment, eye and ear protection MUST be worn
