Avarice Posted February 28, 2006 Report Share Posted February 28, 2006 Can anyone give me an experiment in which K or Na is displaced or isolated from a compound such as salt or potassium nitate? Thanks in advanced. Quote Link to comment Share on other sites More sharing options...
Jay-qu Posted March 1, 2006 Report Share Posted March 1, 2006 This would be very hard to do at home and even in a basic science lab.. You have to use a method of electrolysis of molten NaCl using lots of electricity and making sure that the products (Sodium mainly) dont come in contact with the air, otherwise you could end up in a bit of trouble... Quote Link to comment Share on other sites More sharing options...
Avarice Posted March 1, 2006 Author Report Share Posted March 1, 2006 I see.I have already experimented using a 1/2" diameter KCl crystal, melted down and kept in molten form, and electrolyzed with with 12v DC, plain copper wires.. the resulting substance just seemed to be KCl, just remelted and let to cool. I imagine the electrolysis would cause copper chloride instead of releasing the Cl from the mixture itself, but..any helpful info? Still learning the basics. Quote Link to comment Share on other sites More sharing options...
Jay-qu Posted March 1, 2006 Report Share Posted March 1, 2006 In theory that is a high enough voltage, but you will probably still need to bump it up or leave it for longer periods of time - not unattended. You should use inert electrodes not copper wires - so something like carbon or platinum. I dont recommend doing this because elemental K is very dangerous, I suppose you already know this and thats why you want to get some, take caution all it needs to do is come in contact with small amout of water and you will be getting fireworks... Quote Link to comment Share on other sites More sharing options...
Avarice Posted March 1, 2006 Author Report Share Posted March 1, 2006 Inert electrodes, thanks! Indeed I understand it's quite dangerous, I have prepared for such disasters.. however I am not trying to isolate a large ammount, just enough to verify that it is indeed potassium, and to realize that I was successful in isolating it. I'd like to start a collection of somewhat pure elements that I was able to isolate on my own. You've been extremely helpful :hyper: also if I may ask, are Pt and C inert electrodes in any compound or just this instance? Thanks again.edit: I just realized K boiling point is 759 C, while KCl is *melted* at 771 C.. I hate to ask these kind of questions in ignorance, but how am I going to electrolyze the element aside from gathering it as a gas from the anode? Forgive my ignorance, perhaps I should learn how this is done before trying to do it. Quote Link to comment Share on other sites More sharing options...
Jay-qu Posted March 1, 2006 Report Share Posted March 1, 2006 No, because they must conduct electricity - pure carbon in the form of graphite is the easiest to get hold of and probably much cheaper than Pt :hyper: The problem with a small amount is that your electrodes are going to have to be close together and then that means that the products and going to be close together aswell.. Which can give them a chance to react again.. Quote Link to comment Share on other sites More sharing options...
Avarice Posted March 1, 2006 Author Report Share Posted March 1, 2006 I see what you mean. I'll try to get hold of a stick of carbon, probably order online. Have you tried this experiment yourself? Quote Link to comment Share on other sites More sharing options...
Jay-qu Posted March 1, 2006 Report Share Posted March 1, 2006 NO, not game enough - I have done electrolosis with inert electrodes heaps, got many weird and wonderful things. I have also done some setting up of galvanic cells ie the opposite, making electricity Quote Link to comment Share on other sites More sharing options...
Avarice Posted March 3, 2006 Author Report Share Posted March 3, 2006 Just an update..In lieu of carbon electrodes, I decided to see if ordinary pencil lead (graphite, or carbon) would conduct electricity.. it did, so I used pencil lead from these rather large pencils I had. 12 volts DC (pencil lead as conductor on + and -), molten KCl (half a cups worth in a stainless steel container, melted with propane torch), and here we go. I wish I had labelled the terminals, but here are my results: One of the electrodes formed a deep red liquid around it, and this liquid seemed to move from that electrode away from it.. the other electrode seemed to do nothing special. I kept the reaction going, and the molten KCl itself began to turn red hot (looked like magma).. after about 2 minutes the graphite was dissolving, so I halted the reaction. The KCl hardened very quickly, leaving a layer of reddish/brown solid on top (completely seperated, you could see where it actually layed on top of the molten KCl), and KCl on the bottom. The reddish brown solid did not react to water, therefore I don't think it was K. I read somewhere that Potassium will dissolve back into the molten KCl extremely quickly once it is formed.. I'm assuming that the reddish brown solid was a result of performing the electrolysis within a stainless steel container. Next time I will use actual carbon electrodes and a neutral container. Quote Link to comment Share on other sites More sharing options...
Jay-qu Posted March 3, 2006 Report Share Posted March 3, 2006 ok... was this reddish brown liquid transparent? I am not sure what it could have been..:shrug: Quote Link to comment Share on other sites More sharing options...
Avarice Posted March 3, 2006 Author Report Share Posted March 3, 2006 Only way I can describe it is, it looked like orange/red Playdough was placed on top of the KCl.. except it was the same hardness as the KCl.. I'll have to try again later with proper items. Quote Link to comment Share on other sites More sharing options...
Jay-qu Posted March 3, 2006 Report Share Posted March 3, 2006 I see. Well colours of that type normally tend to be transition metal ions, such as iron - Im not sure if the stainless steel was what reacted but there seems to be little other possible source. Quote Link to comment Share on other sites More sharing options...
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