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Electrolysis - Help?

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Nicole Dainty Nicole Dainty 4360 Points

Hi All, I am a middle school science teacher, and I am responsible for organizing our middle school science fair. I have one student who wants to build an electrolysis device as an engineering project this year. I explained to him that he'll have to have a safe area to do this experiment, in particular because hydrogen gas is flammable. I have reservations about this project for a middle schooler, but he is a very motivated student and he has parent support. So, I have attached his drawing of his prototype. I don't have much experience with electrolysis - it's not in my curriculum and I haven't done it since college! Does anyone have any feedback on his device or advice regarding this type of project in general? I'd appreciate any experience you can share with me! Thanks much! Nicole


Betty Paulsell Betty Paulsell 48560 Points

As a former regional science fair director I would be sure that this is totally under parent supervision or find a mentor who has knowledge of the process to help the student. Also, when the student presents the device for display I would suggest allowing pictures and diagrams only. I did a search in the Learning Center and found a couple of web seminars and podcasts about electrolysis. Here is the link. Good luck.

Carolyn Mohr Carolyn Mohr 92316 Points

Hi Nicole,
I am having difficulty visualizing an experiment with the apparatus. Perhaps you could answer a couple of questions so that we readers have a better understanding of what the student is planning to do with this apparatus and how his/her project falls under the umbrella of being a science fair project. Do you have a regional and state science fair that your students' projects might be sent on to if they do well at the local school competition, or do you just have a school fair? The reason I ask, is because in my mind, design engineering challenges are slightly different from science fair projects. They often do not have all of the steps of the scientific method and are more the designing, building and testing of prototypes.
Finally, safety-wise, you are right to be concerned since hydrogen gas will be generated. Your state or regional science fair organization will have specific guidelines and rules that you will need your students to follow at the local fair in order to have compliance if their projects are chosen to go on to the next level of competition. For example, are they allowed to have this type of apparatus on display and/or functioning during the fair? I think Betty's idea is an excellent way to remove some of the safety concerns. You could have the student conduct any experimenting involving the generation of the gas at school in your lab under your direct supervision in order to eliminate any other safety concerns.

You have a lot on your plate. Perhaps, you might be interested in my state/regional's website. It has lots of great information about the safety of projects. Here is the URL for the safety section: IJAS Safety
(I am assuming your student will be using low amperage - a 6 or 12 -volt electrical source.)

Ruth Hutson Ruth Hutson 64765 Points

Hi Nicole,

Hmmm, this is a tough problem to approach. As a teacher, you should applaud your student for taking the initiative to design this apparatus. However, after looking at his design, I am a little concerned.

I do an electrolysis demonstration in my high school chemistry class. I feel that it is more safe for me to demonstrate this reaction rather than have my students perform an experiment themselves. This is especially important since both hydrogen and oxygen are being produced. The apparatus I use separates the hydrogen and oxygen into separate tubes. I've included an artist representation of the apparatus I use.

My concern with his design is that it does not allow for separation of the oxygen and hydrogen. That could be a dangerous safety hazard. Additionally, I would also be concerned that he is building this apparatus without adult supervision. Electricity and water are not things that should be taken lightly. I also wonder about the feasibility of his design. When water is electrolyzed in the chamber, there shouldn't be any left over to recirculate. If the system runs dry, is there a chance to overheat?

Send us more information about what is happening after the gas leaves the electrolysis chamber.

Nicole Dainty Nicole Dainty 4360 Points

Thanks so much for your replies so far. A bit of background on my science fair: we have our local (school) fair, then winners proceed to the regional fair, and possibly to the state fair (IN) from there. Students can choose between a science project and an engineering project. His device would not be allowed in the science fair as no projects involving electricity can be displayed according to our regulations. This student wants to build this electrolysis device as an engineering project. In addition to the safety concerns I've discussed with him and his mom, I have talked to him about the fact that the product of an engineering project normally is built in order to address/solve a real-world problem. I have asked him to think about how his electrolysis device would solve a problem as many effective and even inexpensive options already exist. As for other questions about what will happen to the products afterwards, I will discuss with him ASAP and return to the forum!

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