TGT
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Magnesium Chloride to Magnesium Metal
Hello all! I am a new member here and this is my first post, but not my first time visiting. I have been lurking the forum for ages now and have
always been annoyed of the fact I could not respond. So I thought it time to actually become a member and hopefully be useful here along with the
ability to receive help from other similarly interested people. It seems this place is filled with knowledgeable users and in my opinion is the best
place on the net for what interests me.
I have one small question that I cannot seem to find an answer for. I am interested in trying to create powdered magnesium metal with electrolysis.
I have seen it done with many other chemicals, but never Magnesium Chloride. I am thinking to super saturate water with MgCl2 and use around 5 volts
with 20 amps to electrolyse the solution and hopefully form Magnesium metal. It should already be in powdered form when filtered and usable when dry,
or at least that is what I am hoping for.
I have done a previous experiment to get powdered silver by mixing water with Silver Nitrate and then placing copper in the solution to eventually get
powdered silver. Although the reaction is different, I am hoping something similar to happen from the cathode or anode to develop a powdered metal.
So my question is, what material should be used for the cathode and anode when doing this experiment? Thank you all in advance and I am very happy to
finally be a full member!
TGT
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diddi
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you cannot displace Mg2+ from water. see the redox potential table:
http://en.wikipedia.org/wiki/Standard_electrode_potential_(data_page)
you would need a melt to be able to use electrolysis
you will note on redox potential table that Cu and Ag are both below water, which explains why it is possible for production of Cu, Ag metals in this
way.
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TGT
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Thank you for the info, I will read more about the redox potential and see what can be done. If I find something I can do, I will add to this thread.
I was hoping I could start a new experiment and log it here, but now I might be dead in my tracks. lol.
TGT
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j_sum1
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If you have the equipment to do electrolysis on a molten salt at over 714°C (and safely vent the Cl2) then you can proceed.
If not, then I'm afraid you really are dead in your tracks.
It's always nice to have a clear-cut situation though.
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DraconicAcid
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Quote: Originally posted by j_sum1  | | If you have the equipment to do electrolysis on a molten salt at over 714°C (and safely vent the Cl2) then you can proceed. |
You don't have to melt pure magnesium chloride, though- you could make a eutectic mixture of magnesium chloride, potassium chloride and sodium
chloride, which melts at 475 oC.
http://www.sciencedirect.com/science/article/pii/00134686638...
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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j_sum1
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In the context of this discussion, I doubt it matters.
Anyway, won't the potassium reduce preferentially before the Mg? (I only ask because there is a huge sticky thread here where Mg is used to reduce
KOH to K.)
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Zyklon-A
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Not with the chloride. KCl is more stable then MgCl2 but KOH is less stable then MgO or Mg(OH)2. Thus magnesium can reduce
potassium oxide or hydroxide but not chloride. Same applies to sodium.
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diddi
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potassium has E° = -2.9
Mg =-2.3
Na = -2.7
so displacement order is Mg first, then Na, then K
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