Introduction: How to Obtain Hydrogen and Oxygen Through Electrolysis
You probably know that water is made from two hydrogen atoms and one oxygen atom, but did you know that that they can be separated using electricity? This process is called electrolysis. The chemical equation for this process is: 2H2O->2H2+O2.
Both hydrogen and oxygen are diatomic elements, which means that they need two of their own atoms to exist as an element. Electricity is needed to to split the molecule into individual atoms (again, remember that they are both diatomic elements).
This Instructable shows how you can use simple materials that are easily found in any discount store, to split water and obtain Hydrogen and Oxygen.
Lets get started! And remember, don't blow yourself up (just kidding, it's not that dangerous :)).
Step 1: Gather Your Materials
Materials will need:
- A water bottle:
- The water bottle will be the container to hold the water before it has been separated into Hydrogen and Oxygen. The one I used was from a local dollar store. The model number can be found above, or really any similar bottom will do.
- Salt will act as an electrolyte. Because water normally cannot conduct electricity, other substances must be used. Salt was the cheapest for option for me.
- Rubber Tubing
- 1/4 inch (OD) tubing was used to transfer Hydrogen and Oxygen out of the bottle. I do not recommend going any smaller than this, as the pressure in the bottle will build up quickly.
- Electrical Wires
- There are four wires that you will: 2 red, 2 black. They will need to be about 1' long and have alligator clips on one side.
- Carbon-Zinc D-Cell Batteries
- The D cell batteries are not for supplying electricity for the reaction. The carbon rods inside of them will be used as the electrodes. They must be carbon-zinc, and they must be D cell.
- Power source
- I used a lantern battery to supply electricity, though a car battery or a sufficient number of D cell batters in series would probably work as well.
- Silicone Caulking
- The caulking will be used to seal the cap from leaks. I used silicone tub & tile sealant, but other sealants should work.
- You will also need some other household supplies such as corrugated cardboard, wax paper, and of course, water.
Tools you will need:
- Gloves (a pair that you do not mind getting permanently dirty)
- Basic leather work gloves work well.
- An electric drill and bit set
- Geometry set
- An X-acto knife or box cutter
- Hot glue gun
Step 2: Scavenge the Carbon Rods
This next part should be repeated four times, for each D cell carbon-zinc battery.
Using needle nose pliers, pull up the lip of the steel covering on the battery. Keep on doing this along the lip until the entire lip flips up. Then pull the entire steel covering off.
At this point you may want to put on gloves and put a sheet of wax paper on your table, because inside the zinc case there is an extremely messy black powder called manganese dioxide. Manganese dioxide is very hard to to get off your hands, clothes, and anything it touches. Be careful!!
Next, with your pliers, grab the edge of the steel cap for the positive side and peel it off. The top of the carbon rod should now be visible.
Now that the plastic that was covering the zinc is exposed, peel that off as well. The bottom negative terminal will come off with it, this will leave you with a zinc case that still looks roughly the same shape as a D cell battery. Next, peel off the thick plastic covering that is attached to the carbon rod.
You will now be able to grasp the zinc casing with your pliers and peel that zinc casing right off like you are peeling an orange. There will probably also be paper between the zinc and the manganese dioxide; you will need to remove that also. You are now left with what looks kind of like a black corn dog. Crush the manganese dioxide, and in the middle you will find your carbon rod.
Finally, just wash it and sand the carbon rod.
Step 3: Drill Holes
It has come time to modify your water bottle.
- First find a drill bit that is a little bit smaller than the outside diameter of your tubing and drill one hole at the top of the container.
- Try inserting the tube in the hole. If it will not fit, use a slightly larger drill bit and try again.
Warning! Do not drill a hole larger the outside diametre of the tube.
You must also drill holes for the carbon rod electrodes in the cap of the bottle. To do this:
- Draw a square on the top of the cap
- Make sure the corners of your square are inside of the threads on the cap. You can figure out where the threads are by holding the cap up to a bright light
- For the first four holes use a small bit as the pilot holes. Then, find a bit that is the same size as the four carbon rods and drill a hole at each corner.
Warning! If you wreck the threads of the bottle you will have to buy a new bottle and start this step over again.
Now that you have all of the holes drilled you will need to get a carbon rod into each of the holes. This part is tricky because it should be a tight fit. Ensure that there is a centimetre of carbon rod sticking out the top of the cap.
Finally, apply caulking around the carbon rods.
Step 4: Make a Stand
For our stand we will be using cardboard. It is not the best material as it will wreck if it gets wet. If you have the supplies to use a different material I highly recommend going down that path.
Use the template to make a stand out of cardboard. You will need to adjust the size of each piece to match your water bottle and carbon rod placement.
Trace the template onto a sheet of cardboard.
Now you can cut out all of the pieces using an x-acto knife or box cutter.
Just cut out the ring of the first piece. For the second cut out the ring then cut the smaller circle from the middle at the lines made earlier. For the third piece cut out the square, then the inner circle, then cut the small middle circle into four pieces at the lines we made earlier.
To glue the stand together use hot glue. First glue one ring to both sides of the square; make sure that all of the inner circles line up. Now glue one sector at the edge of on side of the square with one edge of the sector parallel to the edge of the square and the other perpendicular to the edge along the point of the square. Now glue another sector to the one previously glued and to the edge of the square. This is pictured in photos 3&4 for this above do this for every point of the square.
This step may be found a bit tricky, if so you can use the PDF below as a template.
Divide the diameter by two to find the radius and again, with compass, make a circle and make another circle with the same center as the previous circle on the same sheet of cardboard. Repeat this three times to make three rings of the same size. With two of the rings draw a line strait down the middle through the center, from one edge of the circle to the other. Now make another congruent line that is perpendicular to the previous one. Leave one of the rings, and for the third and last ring, create a square around it by using a protractor. For the first side of the square use your protractor to create a line that is perpendicular to one of the diameter lines and parallel to the other, do this part four times rotating the circle 90° each time.
Step 5: Stir Up Electrolyte
For our electrolysis project the electrolyte we will be using is table salt.
Pour about a 1/4 cup of salt into a container. Now slowly stir and add water until the salt is completely dissolved.
Our electrolyte is ready and can be poured into the water bottle. Before you pour it in make a kink in the tube so that no water will flow out. Once the water is in the bottle screw on the cap, and turn the bottle upside down...
Step 6: Start Your Reaction
To put the stand on just put the carbon rods through the inner circle hole and put the cap on the side that is flatter, relative the other side, the picture can explain it better.
Start the reaction by attaching the wires, DO NOT DO THIS INSIDE.
Attach the one wire to each carbon electrode. It does not matter which wire is connected to which electrode. Now connect the other side of each wire to a terminal on your lantern battery. Again, it does not matter which wire touches which terminal.
Look at the the carbon rods, if there is a flurry of bubbles coming from the carbon rods, then your reaction is a success. Those are bubbles of hydrogen and oxygen (and maybe chlorine, from the salt). If not then test all connections and the if your battery is dead, try again.
Thank you for reading!
A huge thanks to The King of Random for inspiring me to make this project from his instructable: How to Convert Water Into Fuel by Building a DIY Oxyhydrogen Generator.