AboutDan Fink Expertise Though my experience is mostly in the fields of electricity, magnetism, and physics, I have a broad science background. My career is in the field of alternative power sources -- solar, wind, water and battery power. But any questions about electricity, magnetism, energy conservation, power generation, electric motors, and even general physics are very welcome--especially from kids. They ask the best questions of all! I pride myself in answering science questions accurately, with ideas for SAFE, easy experiments that kids can perform by themselves--and that let them prove the answers to their own satisfaction. I think science should be fun, and available to everyone, regardless of age.
Experience I have volunteered in our local public schools for 5 years. I currently make presentations at our schools about electricity and magnetism, with a focus on solar, wind, water and other alternative power sources. I try to demonstrate at our schools how easy it is to make electricity, with simple devices using spinning magnets and coils of wire--powered by wind, water, bicycles, gerbils...etc. And of course solar panels! I am the webmaster of Otherpower.com, an alternative energy website. I have lived 10 miles from the nearest power pole for 11 years--I make all my own electricity from scratch with sun, wind and water.
Publications Otherpower.com
Wondermagnet.com
Co author of the book "Homebrew Wind Power" ISBN 978-0-9819201-0-8
My articles appear regularly in such magazines as Home Power and Back Home Education/Credentials BA Technical Journalism
Question QUESTION: I want to prove that there is the Hydrogen and Oxygen in the water electrolysis in the Science Fare. Tell me the full procedure of Electrolysis of water; and which best electrolyte I choose for it. If I choose NaCl an electrolyte , some Cl gas also formed which I doesn't want. What I do to prove the Hydrogen and Oxygen.
ANSWER: Hello Nikhil -- you can of course use pure water as the electrolyte, but it's a very slow process. Adding a salt to the electrolyte speeds things up by making the solution more conductive, but like you said you don't want chlorine. You'll also need to choose something that has a lower standard electrode potential than the H+ ions.
A good choice that's easy to find, cheap, and not very dangerous (except for the pure, explosive hydrogen and oxygen you'll be getting) is Magnesium Sulfate (MgSO4 7H2O). It's also known as Epsom Salts. You'll want to mix it up at a about a 1M solution (246g epsom salts in distilled water to make 1 liter).
Then, all you need is a Hoffman Apparatus, or build your own. Your own version can be as a simple as a glass jar, a 9v battery, and paperclips as electrodes (insulate the eelectrodes by partially wrapping them with electrical tape.) Don't use copper electrodes, you'll get a different reaction going on alongside the one you want. Stainless steel electrodes would be better, and nichrome wire or platinum electrodes would be best.
Then, you'll have to rig a way to collect the H and O2. That's why a Hoffman apparatus is so handy! But google the term and you'll get some ideas of how to construct it.
I hope this helps!
DAN
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QUESTION: You didn't answer the " How can I prove the Hydrogen and Oxygen which are formed" question. Please give me the answer.
Answer Not easy to demonstrate, but easy to prove.
You light the hydrogen with a match...but that's dangerous and they won't let you do it at a science fair.
As for proof -- without a gas detector, you'll have to titrate. It will involve both hydrochloric acid and sodium hydroxide, so again you may not be allowed to do it at the science fair--check with your teacher beforehand!
Here's the link for doing the titration, it's "Part B" here. None of these are chemicals or lab equipment that I actually have around home, so I have not tried this: http://www.woodrow.org/teachers/ci/1986/exp27.html
