Dreamerdan
Harmless
Posts: 1
Registered: 5-9-2017
Location: Somewhere in southern africa
Member Is Offline
Mood: Think of a tree
|
|
Water battery with an electrode of a Magnesium salt.
Hello im very new to this forum and somewhat of a noob to chemistry in general, but I understand a little. Please be gentle with the technical terms!
My problem is this. I read a while ago on the internet - on a website I cant get a hold of but I think it was called peswiki - that you can make a
water battery using a magnesium rod for one electrode and copper for another. I cant seem to get my hands on a magnesium rod and isn't it dangerous in
any case. So I got to thinking. Would it be possible to substitute the rod with a salt of The metal preferably MgOH or MgCO3. I live on a farm so
dolomite is easier to come by from agricultural lime. The hydroxide on the other hand is another matter ive only ever seen it in milk of magnesia
bottles and it's a very low concentration about 8% and it's not solid. But I would have preferred it considering the cation is OH. In the spirit of
avoiding to buy can I make the hydroxide salt at home without requiring a literal nuke or blast furnace!? Or can I go ahead and use the carbonate.
Will it work? Has anyone tried it? Are there better options to make a water battery?
|
|
|
metalresearcher
National Hazard
Posts: 758
Registered: 7-9-2010
Member Is Offline
Mood: Reactive
|
|
Mg(OH)2 and MgCO3 are insoluble in water, so cannot work as an electrolyte. Use MgCl2 instead, or, even just ordinary table salt NaCl.
|
|
|
Texium
|
Thread Moved
5-9-2017 at 10:06 |
Texium
Administrator
Posts: 4581
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
A soluble magnesium salt will work as an electrolyte, but you'll still need a metal anode for your battery (assuming the copper will be the cathode).
Look up a list of redox potentials and see if you can find a metal more reactive than copper that will give you a decent potential difference if you
were to set up a cell with it.
If you don't understand what I'm talking about, you should find an introductory general chemistry textbook (or a website meant to help students) and
read the section(s) on electrochemistry. It won't take very long.
Edit: Also I looked up PES Wiki and it looks like a half-baked fringe/quackery free energy site, so I wouldn't trust anything you read there if I were
you.
[Edited on 9-5-2017 by zts16]
|
|
|
XeonTheMGPony
International Hazard
Posts: 1640
Registered: 5-1-2016
Member Is Offline
Mood: No Mood
|
|
Go to a hot water store they are sold for the anodes to protect the tank, you get aluminum for steel tanks and magnesium for aluminum tanks.
|
|
|
SWIM
National Hazard
Posts: 970
Registered: 3-9-2017
Member Is Offline
|
|
Magnesium rods are available in various sizes on Ebay.
Even magnesium anodes, but I think most of those are for controlling corrosion in buried pipes, boat fittings and such.
Home made batteries aren't necessarily very efficient or durable.
If you want to make your own I suggest you do considerable checking around on various sites before you start investing in actual construction.
Batteries are simple in concept, but the details of making them durable and efficient can be quite complicated.
I agree with ZTS that any sites that mention free energy schemes are very bad sources of information for hobbyists.
They are by and large free money schemes for the site operator by selling advertising space or by popularizing products or information they have a
proprietary interest in. I know a surprising number of people who have been taken in by such sites and wasted money on unworkable projects.
If you want a storage system for some intermittent power source like wind or solar you might want to look into the feasibility of renovating old car
batteries for storage.
I know virtually nothing about that subject, but there are some posts about it on here that seem to be from people who really know what they're
talking about.
If this battery is touted as a means of getting energy from water, I think they're pulling a fast one on you. Any energy it actually produces would
come from the corrosion of the magnesium, which would be an expensive energy source.
[Edited on 5-9-2017 by SWIM]
|
|
|
Sulaiman
International Hazard
Posts: 3695
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Online
|
|
I briefly experimented with magnesium-copper primary cells,
scroll down http://www.sciencemadness.org/talk/viewthread.php?tid=64759&...
magnesium | magnesium sulphate (Epsom salts) solution | membrane (porous pot) | coper sulphate solution | copper foil
I never got it to work as expected;
. the magnesium corroded even when no current was drawn
. I never got the full expected voltage
Magnesium rods are fairly cheap via eBay,
http://www.ebay.co.uk/itm/5Pcs-High-Purity-99-99-Magnesium-M...
http://www.ebay.co.uk/itm/5pcs-Magnesium-Mg-Metal-Rod-High-P...
IF you could ignite one it would make a nice incendiary device,
luckily it is not easy to accidentally light a lump of magnesium.
(I drilled and tapped a 5mm hole in each of mine)
Magnesium alloys can be found in many cellphone and laptop cases.
For your first cell I recommend a Daniell Cell https://en.wikipedia.org/wiki/Daniell_cell
Buy a 6V lantern battery and dissect for four very pure zinc pots, manganese dioxide mixed with carbon powder, and four carbon rods.
Use the zinc to make your cell, clean and save the rest as they are very useful for battery experiments.
I suggest the Gravity Cell on the Daniell Cell Wikipedia page as a starting point as membranes have their own issues.
CAUTION : Hobby Chemist, not Professional or even Amateur
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
