- Categories
- Education and Communications
- Studying
- Science
- Chemistry
Download Article
Shine a light on a unique chemical reaction with our tutorial
Co-authored byBess Ruff, MAand Eric McClure
Last Updated: April 3, 2024Fact Checked
Download Article
- Setting the Experiment Up |
- Separating the Oxygen and Hydrogen |
- Video |
Using a small power source and some electrodes, you can separate molecules of water into hydrogen and oxygen. This process is known as electrolysis. On a large scale, electrolysis is used to create hydrogen power, produce alloys, and create chemicals. Today, we’ll show you how to perform an experiment that replicates this process on a smaller scale.
Simple Experiment to Electrolyse Water
Push two metal pins through the bottom of a plastic cup. Fill the cup with salt water and put the pins on a 9-volt battery. One pin will produce hydrogen gas and the other will produce oxygen. Put two test tubes over the pins to see the gases separate.
Part 1
Part 1 of 2:
Setting the Experiment Up
Download Article
1
Gather the necessary materials. Separating hydrogen and oxygen from water is done through electrolysis. To do this experiment, you will need the following items: [1]
- Table salt (kosher salt is best since it’s always pure NaCl). You can use baking soda if you don’t have salt.
- A 9-volt battery.
- Two metal push pins (or two metal spoons and two alligator clips).
- The metal push pins are easier to use, but we’ll cover both variations. Most tutorials out there use the alligator clips, though.
- Water (distilled water is best, but tap water is fine, too).
- Two glass test tubes.
- A plastic cup.
2
Stick the push pins through the bottom of the cup. The distance between each pin must match the distance between the two terminals on the 9-volt battery (so that the metal on each pin touches each terminal). Stick the pins through the bottom of the cup so the pointy bits are inside of the cup.[2]
- Variation: If you’re using alligator clips and spoons, connect the alligator clips to the ends of the spoon so that each spoon has its own cable.
Advertisem*nt
3
Fill the cup with water and dissolve a spoonful of salt or baking soda in it. By adding salt or baking soda to the water, you increase the conduction of electricity through the water. Add a cup of warm water to your glass and a tablespoon of salt or baking soda.[3]
- Aim for about 1-part salt or baking soda to 10-parts water. If you don’t get any bubbles when you start the experiment, add more salt.[4]
Advertisem*nt
Part 2
Part 2 of 2:
Separating the Oxygen and Hydrogen
Download Article
1
Connect the battery to the pins or alligator clips. If you’re using push pins, set the cup on top of the battery so that one pin rests on the positive terminal and one pin rests on the negative terminal. If you’re using alligator clips and spoons, attach one clip to the positive terminal and one clip to the negative terminal.[5]
- The reaction is starting! Notice how the spoons or pins start bubbling? They’re beginning to separate the hydrogen and water.
- The spoons cannot touch one another. If they touch, the reaction will stop as you break the circuit.
2
Set the test tubes upside down over the pins or spoons. Set the tubes upside down in the water over the pins or directly over the tips of the spoons where the bubbles are coming out. It’s 100% okay if the tubes fill with water—the gas will displace the water. You are now collecting hydrogen and oxygen separately![6]
- The hydrogen and oxygen won’t have a color. You can only see the gas by watching the amount of air in each tube expand. The color of the water will start to turn light brown as this happens.
- How do you know which gas is which? After a few seconds, you’ll notice the gas is filling up in one tube more quickly than the other. The tube with more air is filled with hydrogen. Remember, H20 is two hydrogen and one oxygen, so the tube with twice as much gas is the hydrogen.
3
Dilute the water with vinegar and clean everything once you’re done. Because you removed some of the hydrogen and oxygen molecules from the water, you’ve actually produced lye as a byproduct. Wash the spoons and test tubes with soap and water, and add enough vinegar to the lye water to change the color back to light brown. Pour out the tinted lye water in the sink.[7]
- If you don’t add vinegar to the lye, it may damage your sink or the pipes.
- You’ve also produced a tiny amount of chlorine gas during this experiment. Don’t worry though, you haven’t created nearly enough to be dangerous.
Advertisem*nt
Community Q&A
Search
Question
If we don't have test tubes at home, what should we use instead?
Community Answer
Any clear glass container should work. If you're really desperate, a jam jar could probably work.
Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission.Support wikiHowYesNo
Not Helpful 7Helpful 31
See AlsoElectrolysis_of_water
Ask a Question
200 characters left
Include your email address to get a message when this question is answered.
Advertisem*nt
Video
Tips
Submit a Tip
All tip submissions are carefully reviewed before being published
Submit
Thanks for submitting a tip for review!
You Might Also Like
Advertisem*nt
References
- ↑ https://www.education.com/science-fair/article/water-electrolysis/
- ↑ https://youtu.be/HQ9Fhd7P_HA?t=29
- ↑ https://acswebcontent.acs.org/member_communities/Outreach_Activities.pdf
- ↑ https://youtu.be/T-OwWOYHhMI?t=143
- ↑ https://www.energy.gov/sites/prod/files/2014/06/f16/solar_electrolysisofwater.pdf
- ↑ https://youtu.be/HQ9Fhd7P_HA?t=62
- ↑ https://youtu.be/T-OwWOYHhMI?t=277
About This Article
![How to Electrolyse Water: An Easy Experiment (26) How to Electrolyse Water: An Easy Experiment (26)](https://i0.wp.com/www.wikihow.com/images/thumb/8/88/Bess_Ruff_Photo.jpg/-crop-100-100-100px-Bess_Ruff_Photo.jpg)
Co-authored by:
Bess Ruff, MA
Environmental Scientist
This article was co-authored by Bess Ruff, MA and by wikiHow staff writer, Eric McClure. Bess Ruff is a Geography PhD student at Florida State University. She received her MA in Environmental Science and Management from the University of California, Santa Barbara in 2016. She has conducted survey work for marine spatial planning projects in the Caribbean and provided research support as a graduate fellow for the Sustainable Fisheries Group. This article has been viewed 66,829 times.
2 votes - 100%
Co-authors: 12
Updated: April 3, 2024
Views:66,829
Categories: Chemistry
- Send fan mail to authors
Thanks to all authors for creating a page that has been read 66,829 times.
Reader Success Stories
Bill Robert
Nov 15, 2022
"I was given the task of improving human society somehow and this provided me with a launching platform for many..." more
More reader storiesHide reader stories
If you buy through links on our site, we may earn a commission.
Did this article help you?
Advertisem*nt