K9

I personally have not done it, but tests will hopefully come soon. I haven't been doing much experiment recently because of my organic chem course, but now that it's over I should have time to start experimenting again. Maybe we should al try and compare notes? Just roughly, from what was said in the book about David Hahn - he took the foil and KNO3 and placed them together in foil. Then he heated up oil until it was snapping and crackling and tossed in the foil. He then let it cool down and removed the metal strips which were now potassium as evidenced by the purple colour given off when placed in water.

Just to comment on the actual reaction, it apparently does not need a solvent, and as long as the materials are in contact and heated (and then allowed to react) the reaction should work just fine.

I've given an explanation. Would you care to give one too please?

The point remains - it is a matter of simple reduction potentials. If one reacts Li with KNO3, the Li will reduce the K cation to K metal while the lithium metal becomes oxidized.

I would just like to back up what apathy has stated as it answers the question. Some people might be a bit confused by the terminology. Now of course if you place some lithium in water, it will not have as violent a reaction as sodium which will be less than potassium and so on to cesium having an extremely violent reaction in water. This is due to that electron being "ripped off" of off the cesium. That being so because cesium has the lowest first ionization energy, making it the easiest to lose that electron. Lithium on the other hand is the strongest reducer (as far as elements go). That is why it is topping those reduction potential lists. If you want an extremely strong reducing agent, then you go to LiAlH4 - and there is your lithium. And so because lithium is a stronger reducing agent than potassium, a reaction such as Li + KNO3 --> LiNO3 + K (as shown in the experiment done by David Hahn) will in fact work. I hope this has helped a bit to explain.