The Digital Bits Science Labs are fun science experiments for young children. Kids, make sure you have an adult's permission before trying any of these science experiments.
Digital Bits Science Lab
Science Experiments for Kids, Parents and Teachers
Easy electrolysis – how to make your own hydrogen
A note of caution on this experiment: One of the gasses produced is chlorine. While this is safe on a small scale, you should not replicate on a large scale without safeguards. Thanks to Larry Robinson for this information – for detail, see his comment below this article.
Description:
A simple demonstration of electrolysis – electrocuting water to convert it into hydrogen.
Equipment Needed:
A 9-volt battery
Wire (something low-gauge and flexible is preferred, like copper wire)
Scissors
Wire stripper
(optional, if you’re handy with scissors)
Tape (durable tape is required, like duct tape or electrical tape)
A glass of water
Salt
The Digital Bits Science Lab Experiment:
This experiment is a simple demonstration of electrolysis. Electrolysis is the method of breaking apart compounds into their original elements by passing an electric current through them.
Put simply, this experiment shows that if you electrocute water, you’ll get hydrogen.
First, we need to make the electric device that will make the electrolysis happen: get the 9-volt battery, your wire, the scissors and tape. Start stripping the ends of the wire. You will need two strands of wire at least six inches in length. Use the wire stripper or the scissors to strip the rubber sheath from both ends of each wire with the scissors. This will expose the wire itself:
After you’ve stripped both ends from both wires, take one wire and securely tape one stripped metal end to one terminal of the 9-volt battery. Next, do the same with the second wire – tape it to the remaining battery terminal. The result will be our electrolysis device, all ready to go:
The rest is easy:
Get your glass of water. Put a tablespoon or two of salt into it. Stir the salt to dissolve it. The water will become a little cloudy.
Get the electrolysis device. Dip both ends of the wire into the salt water.
You will immediately see bubbles start to fizzle off of one wire. (If you don’t see bubbles, then check to make sure that your wires have a good connection to the battery, and that the battery still holds a charge.)
What’s happening here? These instructions are simple do-it-yourself electrolysis: when you electrocute water (which is made of hydrogen and oxygen), the electricity breaks apart water molecules. The bubbles you see are the hydrogen from the water being released. Salt water improves the electrolysis reaction - fresh water (like in the picture above, since cloudy salt water was difficult to photograph) will still give you bubbles of hydrogen, but it won’t be as impressive as with salt water.
Other articles related to this topic:
- Multimeter experiment with voltage and current
- Why is it easier to swim in the ocean? Learn about buoyancy.
- How to electroplate copper
- A classic, easy chemical reaction with baking soda and vinegar
- Multimeter experiments with electricity and water
Thank you guys so much for giving me this science experiment. This really helped me in the science fair, and I now have an A in science.
P.S. science is awesome, and I think that I will continue to use your site to find out information about electrolysis experiments
Thanks
Stephanie,
Thanks for the feedback, and good job on getting the ‘A’!
If you dye the water with food colouring (I made it blue), then the bubbles become even more visible. Thanks so much, I needed to reproduce electrolysis for my project on Michael Faraday, and this was great.
who took those pics?
Hi dude,
I did. Andy Kaiser, the creator and main writer for Digital Bits Science Lab.
it works ,but if i wanted to make a hydrogen with electrolysis how could i possibly make it my sef ,thank you,GBU
Kenny,
I don’t understand your question: As you say, it works. But then you ask how you could possibly make it (hydrogen?) yourself. The answer should be evident: to make your own hydrigen, follow the instructions as specified in the above experiment.
saludos
que sucede si le envio 20000 voltios energia continua.. al agua crees que se me queme la bobina..las burbujas tan solo son hidrogeno.. gracias
What are the best metals to use in electrolysis to produce the most hydrogen?
CAUTION!
The other gas is NOT oxygen. It is deadly CHLORINE gas from the salt.
If anyone repeats this experiment on a large scale, he will poison himself.
The products of electrolysis of salt water are hydrogen, chlorine, and lye (sodium hydroxide).
Sulfuric acid is needed as the electrolyte if you want the other product to be oxygen.
CAUTION!
The other gas is NOT oxygen. It is deadly CHLORINE gas from the salt.
If anyone repeats this experiment on a large scale, he will poison himself.
The products of electrolysis of salt water are hydrogen, chlorine, and lye (sodium hydroxide).
Sulfuric acid is needed as the electrolyte if you want the other product to be oxygen.
———–
although he is right in a way he is not entirely accurate… The salt can make a deadly gas called chlorine but that is if you add too much salt. so levels of each should be carefully added.
Don’t add too much salt (brine solution), otherwise the wire that is producing oxygen will begin producing chloride ions into poisonous chlorine gas. If the water turns, in any form, green, stop the experiment and dispose of the water immediately!
So is the gas hydrogen or chlorine. Could you bottle it and run a car on it. Does the Salt Lake make Chlorine when it gets hit by lighting. Just asking. Can I drink the green water. J/k
If you use baking soda, the positive will produce pure h2 and the negative will produce pure o2. Hydrogen and oxygen. But warning, when the pure hydrogen and pure oxygen mix it creates one of the most explossive gasses in the world.
so what is the best metal to use for maximum gas output and longevity of the metal itself. or is the answer carbon? anybody? and which terminal produces hydrogen the pos or neg? and if its hooked to your cars alternator does physics conservation of energy come into play? whew! im starting to heat up must be the baking soda.
So how do you produce and separate the 2 gasses?
if you add colouring to distilled water to show that without compound ions electrolysis cannot happen will it spoil the experiment?
if i want to do an experiment with distilled water to show that without compound ions electrolysis cannot occur, can i add colouring?
My tests were inconclusive. I tried tap and distilled water with and without baking soda. I ended up with hot water with brownish impurities floating at the top. Also I tried this with 2 different voltages. 110v off home electric and 12 volt off of a car’s battery. So far I had stable bubbling on both with a 10 amp draw using 14 gauge wire. Obviously, the water got hotter and bubbled faster with 110. Basically I ended up boiling off half the water with 110 and creating impurities probably from the water[tap] or from the metals used for current flow. Seems like I need to isolate the oxygen from the hydrogen after the bubbling. I understand that a proton exchange membrane would help. I wouldn’t know where to get one or build one from scratch. In addition, I have seen YouTube videos of the process. Some of them have a collection container piped from the electrolysis unit. That container is partially filled with water. My understanding is that the hydrogen bubbles to the top to a hose leading to a car’s air intake. Are the impurities impeding the H2 production or is that simply a byproduct of hydrogen bonding with other substances. Any suggestions? I mean so far I’ve built a water boiler and nothing else.
To robert:: Electrolysis only works with DC current. The home electric is AC so it will not work. Brownish impurities might be the wire that you are using and it is eroding it.
true. it also depends on youre mixture. try sulphite
how do i separate the hydrogen from the oxygen?
I did the same thing but instead I took a 12 volt supply,used a zinc plate connected to the negative end, and a magenese plate (or magnesium, i confuse the spelling but it looks like brass) to the positive end. The same thing happend but it seemed no chlorine gas was given off.But the really wierd part is that a lime green gel formed in the middle. The way that this happened was I got the connection between the wire and the plate to spark. And I collected it in a test tube.I sealed it and a couple of weeks later it turned blue. I want to know what it is!
The best solution for the electrolyte is potassium hydroxide but sodium hydroxide, also known as lye or caustic soda is almost as efficient. The easiest way to get this is drano crystal drain cleaner which can be gotten at most hardware stores or at least some type of sodium hydroxide drain cleaner. Just ask for lye drain cleaner. The best metal that is easily obtainable is 316L stainless steel. It isn’t affected by the electrolyte and has good heat characteristics.
Is it possible to electrocute regular tap water? could this be a way to purify water?
thanks a lot but my science teacher is mean so how can you trap the hydrogen and prove thats what it is without blowing stuff up?
Your class project has probably come and gone but here is some help after the fact.
Hydrogen and Oxygen need to be collected at the electrodes.
The easist way to see how it is done is by typing Hoffman Electrolysis Apparatus into your browser and following the search engine leads to a picture of the device. You can even buy one for less than a hundred bucks at:
http://www.sci-supply.com/closeup.asp?pid=145&offset=0
Part No: HEA01
$89.95, if they have them in stock. There are other vendors.
If you are trying to produce Hydrogen, nickel, platinum, palladium and steel work well. Nickel has a lattice structure similar to nickel.
Palladium is used in Cold Fusion experiments. This metal absorbs hydrogen.
I would advise using one electrode of Nickel and the other mild steel.
6-12 Volt DC power supply. I use a battery charger with 6-12 VDC and current settings of 2-10 Amps.
Balloons can be used to collect the gases and then you can light the one with hydrogen in it to show the presence with a bang or simply let the filled balloon float away showing lighter that air gas (Hydorgen) filled the balloon.
Always perform this experiment in a well ventelated room or outdoors.
Best wishes
M.Kaminski