[DFliyerz]

I know this is strange, but would it be possible to make elemental magnesium from magnesium sulfate in a reaction similar to the reaction between iron and copper sulfate, or by some other method? I could go out and buy it, but trying to figure out how to make it from household materials is half the fun!

[Hunter2]

Magnesium you can obtain to do electrolysis of meltes magnesium salt. But Sulfat is not the right one , because melting point to high. Better is to use the Chloride, bromide or Iodide. Other option is to react a slat with an other element like potassium, etc. But I dont think you have this available.

[Arkcon]

If you understood the table of electronegativities, you'd see that it was a simple problem.  You'd just need something more electronegative than magnesium to replace it in the salt.  http://en.wikipedia.org/wiki/Electronegativities_of_the_elements_%28data_page%29#Electronegativity_.28Allen_scale.29  You can choose sodium metal, as an example.  This should give you a hint, that what you suggest is practically impossible, even if theoretically possible.  Check the wikipedia pages for the discovery of some of the more reactive metals -- calcium, magnesium, lithium, sodium you'll see that Humphrey Davy tried many such tricks before he started working with electrolysis:  http://en.wikipedia.org/wiki/Humphry_Davy#Discovery_of_new_elements

[DFliyerz]

By the way, the reaction I was referring to between iron and copper sulfate is where iron is placed into a solution of copper sulfate and the ions exchange to form copper and iron sulfate. However, I'm under the impression that magnesium is the most reactive metal that doesn't react with water, meaning it would be hard to find a metal for it to replace in a solution.

[Hunter2]

In solution its no way for magnesium, because all the metals magnesium included will be dissolved in water by releasing of hydrogen.

[Zyklonb]

Arkcon, electronegativity is useful, but in this case Gibbs free energy is the key.
For example: Potassium has a much higher electronegativity then magnesium, but this reaction occurs:  K₂O + Mg → 2 K + MgO. Why? Because ΔG < 0. But this reaction does NOT occur: 2 KCl + Mg → 2 K + MgCl₂. ΔG > 0.
The simple reason is that potassium bonds less strongly to oxygen than does magnesium, but it (potassium) bonds much more strongly to chlorine than magnesium does.
Although I don't know why, I expect it is because the equimolar proportions produce a stronger bond than when one set of ions are in double the concentration of it's oppositely charged ions in the crystal lattice. eg. MgCl₂ is weaker than KCl and K₂O is weaker then MgO.

[Zyklonb]

I'd like to add to my previous post.
Mg actually can reduce  KCl under high vacuum at over 600 degrees C.
I'm going to try this at some point.

[billnotgatez]

I'd like to add to my previous post.
Mg actually can reduce  KCl under high vacuum at over 600 degrees C.
I'm going to try this at some point.

As a home project - WOW!

[Zyklonb]

Yeah, I've got the reaction chamber welded together, and everything else nearly ready. I'll post it if it works properly. It's really more suited for cesium, but I'll try potassium and sodium before I drop the big bucks on cesium salts.