My variant on this experiment:
I use a plastic coke bottle. Two electrodes (stainless steel) are inserted through the lid. Small piece of plastic keeps the electrodes close without touching. Plastic tubing is threaded through a hole in the lid. Lid is sealed up with epoxy gunk so that if it wasn’t for the hose, the system would be airtight.
Electrodes are long and thin and extend nearly to the bottom of the bottle. Tap water is used with NaOH as an electrolyte. (Works really well.) Bottle is nearly full so that there is very little air gap at the top.
Experiment can work in several ways:
- quick observation shows that twice as many bubbles collect on one electrode.
- Gas liberated is a mixture of hydrogen and oxygen in stoichiometric ratio. Nice explosive mix. It is possible to collect the gas using a water bath with detergent and create a bubble raft. Touching a match will give a very significant bang.
- For even greater effect the gas can be collected under water in a zip-seal plastic bag. It might take some time to fill. Do not explode it inside.