Electrolysis of water as a school science project

A. Scott, I've been out of high school since long before you were born, but as I recall . . .

You put two glass jars into the electrolyte in the experiment pan, and fill them with the electrolyte liquid. Then, keeping the open end down, you position them over the two electrodes. The hydrogen and oxygen rise into the bottles and are captured, driving the liquid out of the bottles.

It should be pretty easy to see which bottle has collected twice as much gas, but you confirm it by putting a glowing splint into the oxygen and watch it flame up, and you light the hydrogen and listen to it pop.

A. Have you experimented with square wave pulses to the terminals to split the water molecule in a much faster and cheaper way?

A. Hi P. Can you be more explicit on your needs and restrictions? I'm afraid as it stands you've posed an oxymoron because whatever you use to compress it is a compressor :-)

Regards,

A. You are asking someone else to do your work. Life does not work that way very often, and normally only after you have done some home work. No knowledge. Why not start with a dictionary. Follow that up with an encyclopedia. Follow that up with a high school chemistry book or lab experiment book. Then you can hit the internet for exotic permutations to your experiment. Then you can ask for specific help.

A. The simplest way is to connect two copper wires to a small 9V battery (the type you can buy in supermarkets for smoke detectors,radios etc) and put the other two ends into some water that contains a pinch of washing soda ⇦ this on eBay or Amazon [affil links] (literally a few crystals). One of the copper ends will produce oxygen and the other hydrogen. Which is which? - You tell us. You can refine the technique by using a split cell, such as two burettes joined together near the base and with electrodes stuck into them.

A. Some good sites can be found at Google. Just try to go to www.google.com When you are there just search for-- Electrolysis of Water You will probably get 20 different sites with 4-8 grade level projects.

A. Hi, folks.

Trevor's instructions are good, but it can be a nice idea to capture those gases that he describes. A pretty standard way to do that is to put glass bottles into your tank, let them fill up to the brim with your water and washing soda ⇦ this on eBay or Amazon [affil links] solution, then turn them upside down (open end down) positioned over or around your electrodes. As the gas bubbles that you are generating rise, they will be captured in your bottles. Good luck.

Regards,

A. Hi Praveen. Please spend a couple of paragraphs introducing yourself and your situation. We don't know if you are a pre-teen student looking for a quick work-around because platinum electrodes are expensive, or if you are a post doc who has spent years in this field optimizing the electrolysis of hydrogen and feels that platinum isn't efficient enough. Thanks for your understanding.

Regards,

A. Hi Kishor. The shorter the question, the harder it is to answer usually -- so if you spend a paragraph or two clarifying your question, I'm sure we can answer you better :-)

I don't know if you are seeking a textbook with the answer, some references to real world installations and the results they achieve, or an experimental procedure you can try. And I'm not sure if you impart the same meaning as I do to the word "efficiency" -- to me it's a comparison of the actual amount of oxygen liberated by electrolysis compared to the prediction from Faraday's Law of Electrolysis.

96485 coulombs (ampere-seconds) of electricity will liberate one gram equivalent weight of oxygen if the process is 100% efficient. So try your electrolysis experiment, recording the current and time, and capturing the oxygen in an inverted glass bottle. From its weight or volume, determine the quantity you captured, and compare it to the amount predicted by Faraday's Law. Good luck.!

Regards,