TheGarbageManCan
Harmless
Posts: 4
Registered: 16-3-2011
Member Is Offline
Mood: No Mood
|
|
Elemental iodine to potassium iodide help.
Hello everyone!
I need to make some potassium iodide for af leaching experiment, sinse iodine is insoluble in water.
I have some elemental iodine crystals, but i cant get Koh as the synth ask for..
So i wonder if there were any other ways to make it?
I got some NaoH could it substetute the kho in the synth?
Hope anybody can help me.
Thegarbagemancan.
|
|
|
woelen
Super Administrator
Posts: 8014
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
Tell more about the "af leaching experiment", otherwise no sensible answer can be given.
Btw, adding KOH to I2 does not only make KI, but also KIO and (after some time) KIO3. Similarly, NaOH makes NaIO and NaIO3.
|
|
|
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination! 
|
|
It should be easy to get potassium hydroxide as it is widely used for biodiesel.
You can substitute sodium hydroxide and end up with sodium iodide but it is hygroscopic.
|
|
|
Chordate
Hazard to Others
Posts: 108
Registered: 23-2-2011
Member Is Offline
Mood: No Mood
|
|
Iodine is "relatively" insoluble in water, but not totally insoluble. Potassium iodide is very water soluble, in fact it is used to increase the
solubility of elemental iodine in water by forming the I<sub>3</sub>- ion.
As was mentioned above, reacting a metal hydroxide with elemental iodine may not accomplish what you are setting out to do.
You should share the exact details of what you are trying to accomplish because the reactions which form metal halide salts can be rather dangerous
and you don't sound too experienced.
[Edited on 16-3-2011 by Chordate]
|
|
|
TheGarbageManCan
Harmless
Posts: 4
Registered: 16-3-2011
Member Is Offline
Mood: No Mood
|
|
Hello All.
Allright i Will try to explain better.
I wont to make a tincture af iodine, And since iodine is only slightly soluble in water, i need to make some potassium iodide, to help my water to
hold some iodine.. I need to make a 10% solution of iodide,'then i will use that for leaching precius metals.
Now since koh simply is not legal here, i need to find another rute to get potassium iodide, or sodium iodide.
Please tell my if i need to explain more thank you.
|
|
|
MrHomeScientist
International Hazard
Posts: 1806
Registered: 24-10-2010
Location: Flerovium
Member Is Offline
Mood: No Mood
|
|
I don't see why sodium iodide wouldn't work for that purpose. All you would need is the iodide ion to get your iodine in solution, right? So just
replace KOH with NaOH and you should be good to go.
Or if you really need the KOH, I suppose you could try to synthesize it using other potassium salts that might be more readily available. For example,
the wiki lists this as the historical method of preparing it:
Ca(OH)2 + K2CO3 --> CaCO3 (s) + 2KOH (aq)
|
|
|
TheGarbageManCan
Harmless
Posts: 4
Registered: 16-3-2011
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by MrHomeScientist  | I don't see why sodium iodide wouldn't work for that purpose. All you would need is the iodide ion to get your iodine in solution, right? So just
replace KOH with NaOH and you should be good to go.
Or if you really need the KOH, I suppose you could try to synthesize it using other potassium salts that might be more readily available. For example,
the wiki lists this as the historical method of preparing it:
Ca(OH)2 + K2CO3 --> CaCO3 (s) + 2KOH (aq) |
Thanks.! Yes sodium iodide should do the job.
Then ill just swich koh with Naoh and ill be hold thanks guys!
|
|
|
TheGarbageManCan
Harmless
Posts: 4
Registered: 16-3-2011
Member Is Offline
Mood: No Mood
|
|
I use 11g of Naoh desolved in 250ml of water, then with a litle heat i desolve 25g iodine. i let it cool and filter it, then i boil it Down and
collect the sodium idode crystals/powder.
Then ill take 5g sodium iodide and desolve in 100ml water. Now Iam able to desolve 10g elemental iodine in that to get a tincture of iodine aka
lugols.. Right?
|
|
|
redox
Hazard to Others
Posts: 268
Registered: 22-2-2011
Location: The Land of Milk and Honey
Member Is Offline
Mood: Chalcogenetic
|
|
Well, you won't have pure sodium iodide. Elemental halogens dissociate when treated with base.
I2+ 2NaOH => NaOI + NaI + H2O
When you boil it:
2NaOI => NaI + NaIO3
So your product will contain iodide, iodate, and hypoiodite. But this should be fine for your purpose.
My quite small but growing Youtube Channel: http://www.youtube.com/user/RealChemLabs
Newest video: Synthesis of Chloroform
The difference between chemists and chemical engineers: Chemists use test tubes, chemical engineers use buckets. |
|
|
#maverick#
Hazard to Others
Posts: 209
Registered: 7-4-2011
Member Is Offline
Mood: hybridised
|
|
wait pardon me if im understanding wrong, you want to make a tincture correct? if thats the case cant you just use iodine and ethly alcohol as the
solvent, it is very soluble in it (20.5 g/100 ml at 15 °C, my buddies use everclear to make tinctures of stuff, i believe the stuff you buy from the
store is 2% iodine
|
|
|
Neil
National Hazard
Posts: 556
Registered: 19-3-2008
Member Is Offline
Mood: No Mood
|
|
I seem to recall reading that alcohol/iodine solutions won't work in leaching metals.
|
|
|
#maverick#
Hazard to Others
Posts: 209
Registered: 7-4-2011
Member Is Offline
Mood: hybridised
|
|
yea probably wont but hey its worth a try
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
