This Instructable is not only my first... it is also for the Science Fair contest.
Step 1: The Parts
- A wall transformer ($4.77), which is available here on Amazon.com:
- Water ($0.00), which is usually freely available
- A bowl ($0.00 - $0.06), which can be replaced with anything that can hold water. A cheap bowl is available here on Amazon.com: http://www.amazon.com/Pfaltzgraff-Flower-Garden-Melamine-cereal/dp/B0001GUCCE/ref=pd_bbs_4/103-7672438-6241403?ie=UTF8&s=home-garden&qid=1188382928&sr=8-4
- A small water bottle ($0.00 - salvaged) or test tube ($24.99), which is available here on Amazon:
- Salt... optional
Step 2: What to Do
Next, cut the plug off of the wall transformer. Next, install a fuse to prevent the transformer from breaking in the event of a short. A good fuse is available here on amazon.com. In addition, you can screw on a switch like this. Separate and strip the two wires (you can get a wire stripper here: http://www.amazon.com/Shooter-Tubes-Set-With-Stand/dp/B000COCCX2/ref=pd_bbs_1/103-7672438-6241403?ie=UTF8&s=home-garden&qid=1188383061&sr=8-1 ). Plug the transformer in and submerge both leads in water. To enhance production, you can use pencil graphite by sharpening both ends of a pencil.
One should be rapidly generating bubbles, which are full of hydrogen. Once you know this works, go ahead and tape the lead that does not generate bubbles to the side of the container (still under water). Next, take a test tube or bottle filled with water and while keeping the bottle/tube filled, submerge the open end under water. This prevents air from entering. Thread the wire that generates bubbles into the tube.
Step 3: Other Capturing Ideas
If you like explosions, you have two options:
Remove the bottle of hydrogen and stick a match inside. BOOM!
Use one bottle to capture both gases. This creates the perfect mixture for an explosion. Be careful!
Please not that using salt produces chlorine. Because chlorine is heavier than air, it will fall to the ground. Chlorine is a very dangerous chemical that can suffocate you. To prevent a catastrophe, use another bottle/test tube to capture it.
Another alternate is to use baking soda instead of salt. This will produce oxygen instead of chlorine.
Step 4: Holding the Bottles
I hope you enjoyed this Instructable. While the concept is not new, using a wall transformer is a unique and inexpensive solution. This is a fun experiment... but as with all explosions, be careful!
Step 5: Explanation
When current from the wall transformer passes through the water, the water molecules are split into hydrogen and hydroxide ions. The lead with bubbles, which produces Hydrogen, can be explained through the following equation:*
2H2O(l) + 2eÃ¢Ë†â€™ Ã¢â€ â€™ H2(g) + 2OHÃ¢Ë†â€™(aq)
The other lead, which produces nothing unless a better electrode, like graphite or platinum is used, can produce hydroxide. The formation of hydroxide ions then turn into oxygen (or chlorine if salt water is used). The following equation* defines the reaction:
2H2O(l) Ã¢â€ â€™ O2(g) + 4H+(aq) + 4eÃ¢Ë†â€™
The overall reaction is defined in the following equation:
2H2O(l) Ã¢â€ â€™ 2H2(g) + O2(g)
NOTE: equations are from here.