haydz
Harmless
Posts: 21
Registered: 1-3-2005
Location: New Zealand!
Member Is Offline
Mood: No Mood
|
|
KOH crystals for electrolysis
Hi
I've just been reading a couple of books and one of them mentioned the electrolysis of potassium hydroxide to form potassium metal, it was
described as being done by letting the KOH absorb some moisture in the air before electricity is run through it. It also said that the metal had to be
stored under kerosene as it is very reactive. My question is, can I grow crystals in the same way as sugar crystals but for KOH (as my KOH is in the
shape of a flat disc) for use in electrolysis (wouldn't the KOH just stay dissolved or what?) or am I missing something?
Thanks. Hayden.
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
Don't worry about it, it has a low melting point. Mind that it attacks damned near everything, glassware is out of the question for anything for
than a short test. Easy enough to throw it in a steel dish and set it on the hotplate.
Tim
|
|
|
haydz
Harmless
Posts: 21
Registered: 1-3-2005
Location: New Zealand!
Member Is Offline
Mood: No Mood
|
|
argh thats so easy compared to what i was going to do.
for the electrolysis, have i missed anything out.. just leave the clump of KOH in the air for a while till its moist and then run electricity through
it?
|
|
|
neutrino
International Hazard
Posts: 1583
Registered: 20-8-2004
Location: USA
Member Is Offline
Mood: oscillating
|
|
I don't see why moisture is in any way necessary here. I'm sure the standard sodium synthesis has been described in a thread somewhere; it
should be about the same thing.
|
|
|
darkflame89
Hazard to Others
Posts: 255
Registered: 1-3-2004
Location: With probability 1, "somewhere" in this
Member Is Offline
Mood: No Mood
|
|
Sounds like what BromicAcid did previously. IIRC, he put a little a NaOH on a watch glass, sprayed some moisture onto it and applied current to it.
The water was first driven off. Due to the heat from resistance in the mixture, the space between the electrode was kept molten for sodium to be
produced. The spacing between the electrode have to small.. There's a page in the forum that describes what he did, but i have forgotten where it
was..
Ignis ubique latet, naturam amplectitur omnem.
|
|
|
BromicAcid
International Hazard
Posts: 3253
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
I believe Davy is the one that actually preformed this experiment. He sat a block of KOH on a platinum sheet and drilled a hole in the top that he
filled with mercury, he inserted the cathode into the mercury and connected the bottom sheet to the anode, when the block became damp from atmospheric
moisture it was able to conduct, the circuit being around the block and electrolysis was able to commence giving a potassium amalgam at the cathode.
And as for growing a potassium crystal, good luck, your best bet is going to be simply heating KOH till it melts and pouring the shape you want from
it. It will simply solidify into the shape you want that way, just don't have any water in your mold.
[Edited on 6/22/2005 by BromicAcid]
|
|
|
akcapr
Harmless
Posts: 21
Registered: 26-5-2005
Location: Washington
Member Is Offline
Mood: No Mood
|
|
the point of the water is probly to just get rid of the pores/pockets in the compound
|
|
|
chloric1
International Hazard
Posts: 1147
Registered: 8-10-2003
Location: GroupVII of the periodic table
Member Is Offline
Mood: Stoichiometrically Balanced
|
|
| Quote: | Originally posted by akcapr
the point of the water is probly to just get rid of the pores/pockets in the compound |
nope, sorry you are wrong. It is to ionize the alkali enough to conduct then when large amounts of current are going through the heat from the
resistance melt part of the KOH.
Fellow molecular manipulator
|
|
|
haydz
Harmless
Posts: 21
Registered: 1-3-2005
Location: New Zealand!
Member Is Offline
Mood: No Mood
|
|
I see the electrochemical sodium thread, and was wondering if the same procedure/s could be used with KOH rather than NaOH? K is more reactive and so
it might be harder to get the K from it?
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
