Osmium
(Moderator)
05-27-98 11:09
No 109151
      Home-made I2
(Rated as: excellent)
    

This is just an idea, and I have no proof that it really works, but hey, go to the library and check it yerself.
<p>First, obtain some NaI or KI. Dissolve it in water.
Second thing we need is a strong oxidising agent, like NOx (nitric acid + Fe wool), Cl2 (acidify bleach, or HCl and permanganate or MnO2), maybe even H2O2 or HNO3, which is bubbled through the iodide solution, or simply add one of the oxidisers to it. I don't know which one works, read and experiment.
This oxidises the iodide to iodine. Extract I2 with suitable solvent or distill I2 away with a stream of air to separate most of the inorganic shit.
Crude I2 is purified by sublimation. To do this, place crude I2 in a crystallizing dish and add some KI. Fill a large round-bottomed flask with cold water and place it onto the glass pot containing the crude I2. Now carefully heat the crude I2. It will evaporate and crystallize on the outside of the flask. Carefully remove it  to obtain quite pure I2.



Nobody interested?

O. checked it himself. It can be done, of course.
Oxidising agents like H2O2 in dil. HCl, Cl2, nitrite/H+, oxygen with NOx catalysis, K2Cr2O7, KMnO4, MnO2, bleach or PbO2(all in acidic soln) can be used.
The iodine is separated from the reaction mixture by (steam) distillation. Solubility of I2 in H2O is low (0.8g/l), all the crystals can be filtered away. Dry them in a desiccator over conc. H2SO4 or CaCl2 and purify by sublimation. Heat with sand bath. To avoid other halogenides as contaminants, especially when using Cl2 or bleach as oxidiser, grind the raw iodine with powdered KI before subliming.

Voila, OTC iodine, in huge amounts and inexpensive
 
 
 
 
    Tlange
(Junior Member)
05-28-98 02:52
No 109153
      Re: Home-made I2     

Brilliant....now if the RP was only as easy to make...hmmm. ;-)
 
 
 
 
    Osmium
(Moderator)
05-28-98 11:52
No 109154
      Re: Home-made I2     

I'm working on it ;-)
 
 
 
 
    Osmium
(Moderator)
07-01-98 13:41
No 109155
      Re: Home-made I2     

Hope you'll find it now, jimwig.
 
 
 
 
    jimwig
(Member)
10-01-98 02:42
No 109156
      Re: Home-made I2     

Osmium - I have finally found it after almost ten months of searching all over the globe via the net of course. I can finally quit and take a shower- thank God!!!!!
 
 
 
 
    drone 342
(Member)
10-15-98 19:08
No 109157
      Re: Home-made I2     

Os,

Do you have a work-up method for this now?

-drone #342

 
 
 
 
    300 Spartans
(Junior Member)
10-17-98 14:20
No 109158
      Re: Home-made I2     

try gathering the mushing into a pulp pacific kelp boil the shit out of it till dry then add you oxidizer and acids  aka osium let steep filter then heat placeing a round fish bowl over the top of your containerand as the man said Presto! unlimited and cheap supply of iodone crystals
 
 
 
 
    Osmium
(Moderator)
10-18-98 07:13
No 109159
      Re: Home-made I2     

Drone: As I said, solubility of I2 in water is low, as long as no excess of I(-) is around. Simply filter it away or extract with organic solvent.
For bromine I recommend distillation of the reaction, or maybe blowing air through the solution and collecting it in a cold trap. In situ preparation of Br2 is probably best for brominations. I don't think extraction of Br2 is a good idea (cough, cough...). Reagent grade KBr from Merck is on its way to my house, and I will try it when I find the time.
 
 
 
 
    drone 342
(Member)
10-20-98 22:10
No 109160
      Re: Home-made I2     

Os,

The extracting works pretty well for Br2 -- just use toluene. The toluene bromine solution is fractionally distilled (with an aspirator), and pure bromine is aquired. The advatntage is that by extracting with a solvent, you can get the volume of for your starting material for your distillation down, but the purity of the final product up. Nothing to it, though I'm definately interested if you have a better method. I look forward to labnotes. 

-drone #342

 
 
 
 
    HoneyDream
(Junior Member)
07-21-99 08:58
No 109161
      Re: Home-made I2     

Where can i obtain some I2?  sorry to sound lame, but if i have a question and i cant find it on search, or anywhere else the best i can do is ask..  what exactly is I2, iodine crystals?
 
 
 
 
    pebble
(Member)
07-21-99 21:54
No 109162
      Re: Home-made I2     

I know that there are different ways to make iodine crystals and everybody it seems, has their own way. I have found that this works for me and it's quite easy to do. Here is the synth for making iodine crystal using tincture.
 
   Get a one gallon jar. Pour in 16 1oz. tincture bottles that contain 2% iodine, this is two cups. Then pour in a cup of muratic acid. The add two cups of hydrogen peroxide and then a cup of 70% ribbing alcohol. Shake this up and let it sit for 5 min. Then come back and fill the entire jar with very cold DH2O. Cap it and let it stand for 20 min. (Do not shake this time).

   Then get a couple of coffee filters and filter the liquid along with the iodine crystals. Then pour a little cold DH2O to stablize contents and taks your filters and squeeze out all water and then put your iodine crystal in a jar and you'll pure iodine crystals. It's really that easy. Other methods are also similar and others are just hard and complicated and a bullcarp waste of time. Try it and you'll see just how easy it really is.

Pebble

 
 
 
 
    HoneyDream
(Junior Member)
07-21-99 23:17
No 109163
      Re: Home-made I2     

thank you pebble.  one question about that:

At the end, you said filter the liquid in a
coffe filter, squeeze out the water from the
filters and you have pure iodine crystals.
my question is: are you saying the iodine
crystals will get stuck in the filter? as in
the liquids will go through the filter but
the iodine wont, and so all in your filter is
pure iodine crystals?

thankx.

 
 
 
 
    pebble
(Member)
07-22-99 00:37
No 109164
      Re: Home-made I2     

Yes, just filter and at the bottom of the jar will be the iodine. You'll see it when you pour all the contents out. It will look like mush until you squeeze out all of the water. When you squeeze out all of the water, you'll have iodine crystals that the filters contain. Dump these in a jar. These are also light sensitive, so keep them away from light.

Pebble

 
 
 
 
    Soldier
(Member)
07-22-99 03:06
No 109165
      Re: Home-made I2     

A quick way to test the purity of the Iodine from these methods is, take a small amount of I2 (about the size of the head of a pin or a little larger), put in pyrex dish, and heat in some safe manner. The I2 will sublimate. If the residue left is granular in texture then IODIDES are still present which washing with DH2o should take care of.

------------------
A little revolution...is a good thing. Thomas Jefferson

 
 
 
 
    CHEM GUY
(Member)
07-25-99 01:48
No 109166
      Re: Home-made I2     

drone 342,

Last time I checked elemental halogens reacted with unsaturated carbon bonds with or without light present.

Br2 + C6H5-CH3 --> C6H5Br2-CH3

 
 
 
 
    Merry Crankster
(Junior Member)
07-28-99 18:52
No 109167
      Re: Home-made I2     

while dreaming anothers dream I screwed up but the results were exellent, heres how it whent.

   Dreamer misread h2o2 (hydrogen peroxide right) as dh2o(distilled water, right).

1 pint 7% tincture iodine(from feed store)

added to this 3 pints dh20

+ 1/2 cup of muriatic acid(hardwarestore                            stuff cement                                  cleaner)

then said oops that should have been h2o2 insted of dh20.......

so then added 1 pint h202 nothing happening yet. so went to the hive and saw something about bleach and muriatic extraction of Iodine tincture.

so said what the hell and added bleach about 1/2 cup and whalla solution became clear brown color with lotso darke colored cystals floating around in there.

filtered crytals through a few coffee filters  in funnels pressed out extra liquid and air dried an hour or so. Looks like killer Iodine  grey purplish crystle flakes/granules.
dreamed it in Hi/rp reduction at 1 part to 1 part Pephedrine with 1/2 part rp good product 50-60% return.

 
 
 
 
    outlaw
(Member)
07-31-99 00:51
No 109168
      Re: Home-made I2     

Ok I have a friend who has a plastic bag with
containing Organic iodine 40\salt base
ingrredients are ethylenediamine Dihydriodide,salt,artificial color, silicon Dioxide. Also says Salt(NaCI}minimum-87%
maximum-91%. can anyone give advice on what needs to be done to this for clean I2 if anythying. Believe me the search engine has been my life for over a month so if anyone can help Id apreciate it. Happy dreaming to all.
 
 
 
 
    Demented Angel
(Member)
11-21-99 10:54
No 109169
      Re: Home-made I2     

I know this is an old thread, but was wandering around the Hive, came across it, and thought, "Hey, since folks have posted a couple of quick and easy ways to get I2, and since 'How do I get I2?' is a commonly asked question, why dont I go ahead and post a method I came across?"

So here goes.  I came across this method awhile ago, and dreamt that it worked very well.

This was originally posted by cantstanditanymore, and has been rewritten by me because I have misplaced the original document.  Oops! 

DA


Iodine Extraction
-----------------
Originally posted by cantstanditanymore

Ingredients:
   1 pint tincture of iodine (7%)
   3 pints hydrogen peroxide (3%)
   1/2 cup distilled water
   1/2 cup muriatic acid

Other things needed:
   1 gallon jug
   1 set rubber gloves - nothing says cook like iodine stained fingers!
   coffee filters
   more distilled water for rinsing of product

Put tincture, peroxide, acid, and distilled water in your clean gallon jug.  (Note, as with all chem equipment, only clean it with distilled water.)  Cap the jug and shake well.  Set aside for 20 minutes or so.  Go watch an episode of South Park while you wait.  Pour off excess liquid.  Take 2 coffee filters, placing one inside the other, and filter remaining product through the coffee filters.  When filtration is complete, roll up product in filter and squeeze firmly to remove moisture.  Transfer to clean set of coffee filters and rinse crystals with distilled water.   Do this 4 times to clean your product.  Once again, squeeze firmly to remove as much moisture as possible.  Place product on clean, dry filters or in pyrex dish, and set in a dark place to dry.  As soon as is dry, transfer product to dark, airtight container.  Approximate yield, 16 grams.

 
 
 
 
    Demented Angel
(Member)
11-21-99 12:21
No 109170
      Re: Home-made I2     

Oh, one thing I nearly forgot.  Original post told of using pantyhose to filter crystals out.  In my dream I didn't have any hose around so used the coffee filters.  Hose seem like might have worked easier.

DA

 
 
 
 
    Dorian Gray
(Junior Member)
11-25-99 23:57
No 109171
      Re: Home-made I2     

Try this:

1. Dissolve 100g KI or NaI in 300ml 10% HCl
2. Add 100ml H202 (hydrogen peroxide)

As you add the H202, I2 falls out. This can
be filtered off, as it is only slightly soluble in water.
It is a good idea to wash it with some distilled water, as it might still contain some KCl or NaCl.
When I do this in my dreams, I squeeze the filter to get the I2 crystals dry (not completely).
Then it can be purified by resublimation (see above).

reaction mechanism (:-)):

The H2O2 gives off oxygen ions.
These react with the hydrogen ions
from the HCl to form H20. The H202 is now H20, too, since the O left it, because they argued the whole time. Not a very stable relation, that H202.
Now that chlorine ions from the HCl are alone.
But they don't want to be alone. They want to be satified. So they grab the K ions from the KI, since they are stronger than those iodine ions.
Now the iodine ions are alone. And they want to be satisfied, too. So they react with temselves to form I2 :-).

D.G.


 
 
 
 
    Optimus Prime
(Member)
11-27-99 03:44
No 109172
      Re: Home-made I2     

I read where the addition of aspirin to NaI or the like evolves HI (g) which can be piped into dh2o to give aq. HI.

yawn......

OP

 
 
 
 
    myles
(Stranger)
11-03-02 09:56
No 375970
      Re: Home-made I2     

Try this:
1. Dissolve 100g KI in 300ml 10% HCl
                  or in 107ml 28% HCl
                    ->300ml HCl 10% = 30g HCl
                    ->30g HCl/280g/L = 0.107l of 28% HCl
                    ->if using 28% hcl add 126ml h2o also
2. Add 100ml H202 (hydrogen peroxide 10%)(=10g H2O2)
     or 333.33ml H2O2(3%)(10g/0.03g/ml=333.33ml)

2(KI) + H2O2 + 2(HCl) ------>  2(H2O) + 2(KCl) + I2

KI = 166g/mol
H2O2 = 34g/mol
2HCl = 36.4g/mol

SO -> 100g KCl = 0.602 mol
      10g  H2O2 = 0.301 mol 
      22g  HCl = 0.602 mol
->Need pretty exact amounts of potassium iodide and hydrogen peroxide, but excess hydrochloric acid is OK.  Thats why the recipe is for 30g equivalent of HCl when the balanced equation is for 22g HCl.
100% theoretical yield of I2 = 254g/mol x 0.301mol = 76.454g

As you add the H202, I2 falls out. This can
be filtered off, as it is only slightly soluble in water.
It is a good idea to wash it with some distilled water, as it might still contain some KCl.
When I do this in my dreams, I squeeze the filter to get the I2 crystals dry (not completely).
Then it can be purified by resublimation (see above).

reaction mechanism (:-)):

The H2O2 gives off oxygen ions.
These react with the hydrogen ions
from the HCl to form H20. The H202 is now H20, too, since the O left it, because they argued the whole time. Not a very stable relation, that H202.
Now that chlorine ions from the HCl are alone.
But they don't want to be alone. They want to be satified. So they grab the K ions from the KI, since they are stronger than those iodine ions.
Now the iodine ions are alone. And they want to be satisfied, too. So they react with temselves to form I2 :-).

D.G.(original) + Myles(modified)

 


The BEE game is why im here top score 300 points
 
 
 
 
    Osmium
(Stoni's sexual toy)
11-27-02 12:16
No 383866
      > 300ml 10% HCl or in 107ml 28% HCl > ...     

> 300ml 10% HCl or in 107ml 28% HCl
>    ->300ml HCl 10% = 30g HCl
>    ->30g HCl/280g/L = 0.107l of 28% HCl
>    ->if using 28% hcl add 126ml h2o also


You assumed that all the liquids have a density of 1.0. They don't! 28% HCl has a density of ~1.14, and 10% HCl should be around 1.05 if I remember correctly.
 
The error might be small in some cases but rather big in others!


I'm not fat just horizontally disproportionate.
 
 
 
 
    vapotron
(Stranger)
12-04-02 22:32
No 386297
      simplest I2 from povidone feed-stock solns.     

Before I realized I could use ether to x-tract the i2 from the Ka/I soln that resulted from the hyp/hcl additions, I played around with feedstock 1% iodone soln (not povidone, some other shit, real soapy) anyway... I found hcl/hypo didn't precipitate, but formed a dark sludge and seperable light top watery layer. This can also be achieved by gentle heating since it seems to destroy the solvating properties of the shit. So I then proceed to sublime it out of the goo using a big cold finger. It worked but not well. THEN I figured, "I should just distill this shit into dH20 since the soap doesn't come over" SO lo and behold I hooked upi a short pcv tube to a  thermometer adapter on top of the flask and stuck the other end in a jug of dH20. And lo and behold Tons of shiny black crystals dumped into the reciveing jar. You should probably add some sort of trap as when the I2 vapors hit the cold water they SNAP very loudly and cause considerable suck back. but this gave me totally pure super simple I2 fromtheir most prized concoction to keep us from doing just that. Took four hours altogether, haven't really tallied up yield since we lost abunch to fuck ups, breaking flasks (fun) etc. and I'm sure can be tweaked indefinitely for extraction from aqeous solns.
also if you have pure KI Cl gassing is definitely the way to go. And using NP's to extract I2 sure deserves to be explored some more. Have fun....
 
 
 
 
    ussiboy
(Stranger)
03-27-03 22:10
No 421787
      thanks pebble i tried your method and it ...     

thanks pebble i tried your method and it worked fine for me and to think i even never did anything with chem before i got my some real nice iodine crystals
cool
 
 
 
 
    elfspice
(Newbee)
03-23-04 00:40
No 496714
      bubbling...     

so what you're saying is basically boil your iodine after adding HCl and H2O2 in one flask and pipe the vapours into a container of water with ice in it and that's it? that's really neat actually.

I customarily use distilled naptha as a solvent, i was wondering if that would be a good way to fully dry the iodine - separate off the water residual by dissolving the iodine in the naptha and washing off the residual watery stuff. i would think pentane/hexane would be the perfect solvent for this since both dissolve very little water and the distilled fraction that is made boils off mostly before the iodine hits it's sublimation temperature (127*C isn't it?)... then put the iodine in distilled naptha solution on a dish and evaporate slowly,  maybe sitting on something warmish (fast evaporation results in rapid cooling and condensation of water from out of the air)... or maybe in a flask in a hot water bath with a hose feeding over to a drying tube to prevent water from entering while letting the naptha vapours escape.

or simpler: i have a copper condenser, which i dont' think would be suitable to collect the iodine when subliming it, however, it should be fine if a layer of plastic wrap is put around the condenser tip where it goes into the flask to work as a cold finger.

I've noticed those iodine 'washes' in the pet shops too - they contain '.6% available iodine' or something like that, i don't know what the real number of total iodine content is, but it's cheap and comes in a large 500ml container (at that percentage that works out to 3g, where i am works out about half the cost of the wee 25ml bottles from the pharmacy)
 
 
 
 
    elfspice
(Newbee)
03-23-04 03:29
No 496756
      stochiometry!
(Rated as: good read)
    

There seems to be only one main iodine tincture available local to me, a very expensive 25ml with 25g/L each of KI and I2 in alcohol, so i thought i might sit down (while buzzing on some presently but probably not much longer to be legal piperazine stimulant ;) ) and work out the precise stochiometry of the reaction so that it can be done more successfully


H2O2 34.0146g/mol
KI 165.9945g/mol
I2 253.809g/mol
HCl 36.5609g/mol

25g/L KI = 0.150607 mol/L
25g/L I2 = 0.098499 mol/L

25g/L=0.025g/ml

in 25ml, by weight:
0.625g (0.003765 mol) KI
0.625g (0.002463 mol) I2

symbolically:

2(KI) + H2O2 + 2(HCl)
    ------>
2(H2O) + 2(KCl) + I2

molarity:

2x(0.003765) + 0.003765 + 2(0.003765)

the weights of each would be as follows (per 25ml bottle):
KI: 0.625g
H2O2: 0.128g
HCl: 0.137g

the H2O2 needed to provide the
correct amount would be the following,
depending on the concentration of the
H2O2:

1%  (0.01g/ml) 12.8ml
3%  (0.03g/ml) 4.26ml
6%  (0.06g/ml) 2.13ml
10% (0.10g/ml) 1.28ml
45% (0.45g/ml) 0.284ml

the amount of HCl solution at varying
(common) concentrations:

28% (0.28g/ml) 0.4892ml
30% (0.3g/ml) 0.4566ml
31% (0.31g/ml) 0.4419ml
32% (0.32g/ml) 0.4281ml
33% (0.33g/ml) 0.4151ml


Once the proper proportions of reagents are mixed together, the potassium iodide will be turned into potassium chloride and the iodide ion turns into iodine. The usual thing to do from here is to add lots of water to dilute the alcohol and then the iodine will precipitate from the solution. However, this is inefficient in two ways - one, the alcohol, no matter how dilute, is going to cause some amount of iodine to remain in the solution. And every ml of water, which reduces the amount held by the alcohol dissolves iodine to the rate of 0.03 g/100 mL at 20 C, that's 300mg dissolving into a litre of water.

I think the best way to proceed would be to first convert the iodine into salts, then boil it down and all the pesky alcohol goes away. The precise molar amount of base to use on the 25ml tincture bottle to convert the iodine is 0.004926 moles, if NaOH (molar weight 39.99707g/mol) were used, this would mean 0.197g of NaOH per bottle of tincture.

The total number of moles of iodide ions in the solution would thus be

moles KI + 2x moles I2 = moles I+

0.625g (0.003765 mol) KI
0.625g (0.002463 mol) I2

0.003765 + 2x(0.002463) = 0.008691 moles of iodide ions

Okay, so now we have a mixture of sodium iodide and potassium iodide, we can safely boil it down to dryness without fear of losing I2 or stinking and staining up the kitchen ;) both of them melt at 600+ degrees C, so there's no concern of decomposition or anything, one could bake it in the oven at 250C until it absolutely has no moisture left in it.

Thus we have defeated the first source of losses.

then, we have 0.008691 moles of iodide ions which we can turn into half as many moles of I2, so we can then turn it back into iodide ions...

back to the formula:

2(KI) + H2O2 + 2(HCl) ------> 2(H2O) + 2(KCl) + I2

okay so that's
iodide ions 0.008691 moles
H2O2 0.0043455 moles (0.1478g)
HCl 0.008691 moles (0.3177g)

ppl can convert their for their own acid and peroxide, but mine's 280g/L HCl and 3% peroxide, so for me that means:

HCl (280g/L) 1.1348ml
H2O2 (30g/L, 3%) 4.9266ml

per 25ml tincture bottle you start with.

Now with this home made Na/K/iodide salt, which is nice and dry, you can add those two reagents, and since you hardly added any water, it's not hard to dry it again.

Because the whole thing is done with proper molar ratios, one should get around 95% yield. For each little 25ml bottle of tincture, theoretical yield of total I2 is 0.0043455 moles or 1.1029g , so it should be possible to get 1.047g out of each little bottle.
 
 
 
 
    elfspice
(Newbee)
03-23-04 03:41
No 496758
      from kelp?     

Let's say that a person happened to have a quantity of kelp and they knew the amount of iodide ions contained in it, then the same thing could be done to it (well, more or less, but not so stochiometrically accurate), ensure it's iodide by adding the stochiometric amount of sodium hydroxide, then filter it all out, defat the solution, boil it down to dryness then add the peroxide and hydrochloric acid and wash out rubbish with cold water.

does that seem reasonable?

also, as an alternative to sublimation, could one repeat the process? this would isolate the iodine from the kelp and then the second pass of the process would isolate the iodine from the rubish remaining from the first time.
 
 
 
 
    gsus
(Hive Bee)
03-23-04 06:59
No 496792
      kelp, I2, and iodate     

i believe (someone will elaborate, this is well known for sure) that for extracting I2 from seaweeds that collect it, the method is:

  "the seaweed is dried then burned. The ashes are leached and, from the solution, K2SO4, KCl, and NaCl are removed by crystallization. The filtrate is evaporated and the residue treated with H2SO4 and MnO2 or with Cl2. The liberated I2 is collected and purified."

  i love the fact that you're going DIY, but i'd just like to use this post to say that any usa bees who are buying their I2 from tincture or elemental I2, well...that can have a high cost, money and freedom-wise. everyone who sells I tincture knows what is up. maybe they're ok with making money off it, but even then it is still much cheaper to just order some iodide or iodate.

  either one is pretty cheap, usually as USP or ACS grade. some sell high, but some sell low, and in the past i've found ACS KIO3 at very low cost per mole of I2. when you start looking at 500g+ quantity you see that you're better off ordering a lot of this once than going to the tincture. much cheaper per mole. cheaper even if you get way more I2 than you'll ever need.

  since i mentioned the iodate, i suggest everyone try a fun reaction not mentioned in the hive before:
  put some dH2O in a flask. add some oxalic acid. it doesn't have to be very much, but given the cheap OTC-ness of the 99% hydrated acid, add as much as you want. add some iodate or iodic acid or I2O5. heat, and place your sublimation apparatus (like an upside-down flask, jug, or bowl with a ice-filled towel wrapped around it, or a metal bowl containing icewater resting on top) over the neck of the flask immediately. if you add iodate to boiling oxalic solution, you get instant and heavy production of iodine vapor. you will also note vigorous gas evolution. it is CO2, there is no CO formed, or side I products, as far as i can tell.
  the reaction proceeds in direct relation to heating.
  i think that you need at least 2 moles oxalic (don't forget that yours is probably the hydrate if you're actually weighing) per mole iodate salt. or acidify with some other acid, then add 1 mole oxalic. the free acid of course is different, but you might as well add excess oxalic anyways. 

Confucius say: "buy a lifetimes worth of chemicals and glassware now, while iodides, toluene, and everything else is still available. maybe future hold no love for chemist without a license to practice chemistry. buy discreetly and store in remote location"


 
 
 
 
    Osmium
(Stoni's sexual toy)
03-23-04 09:43
No 496815
      > I think the best way to proceed would be...     

> I think the best way to proceed would be to first convert the iodine
> into salts, then boil it down and all the pesky alcohol goes away.
> The precise molar amount of base to use on the 25ml tincture bottle
> to convert the iodine is 0.004926 moles, if NaOH (molar weight
> 39.99707g/mol) were used, this would mean 0.197g of NaOH per bottle
> of tincture.

Basifying I2 and evaporating will produce a mixture of NaI and NaIO3, which on acidification will react back to I2. No need to add H2O2 for the elemental iodine in this case.

The H2O2 oxidation of iodide is slow, and I assume some H2O2 will be lost due to decomposition, so it's not necessary to go overboard with your significant digits during stoichometry calculations, just add an amount that is somewhat bigger than the theoretical requirement.

The iodide/iodate reaction is pretty fast, you mix the solutions and solid I2 will precipitate immediately. If you can get your hands on NaIO3 or NaIO4 and NaI then your I2 problems will be over.

BUSH/CHENEY 2004! After all, it ain't my country!
 
 
 
 
    elfspice
(Newbee)
03-24-04 22:21
No 497087
      hehe     

i forgot what the rules with significant digits was so i kinda winged it (praise bob that spicey is going to redo his highschool chem blush )

okay, so anyway swis found some 'iodine pet shampoo' at his local pet store and the bottle was 30 something and had 19.7mg/ml of 'crude iodine'

swis set up a little thingy like the one with the bubbling and shiot, chucked salt in the shampoo stuff to stop it frothing, and spent several hours being frustrated - it seemed iodine would sublime for a moment or two then stop and all this distilling business starts happening.

Okay, so that was a wrong turn. Upon inspecting the solution after it cooled, swis discovered that it had separated into layers, a reddish layer on top and a thin black layer at the bottom. swis decided that the bottom layer was where all the 'crude iodine' was hiding, and after rinsing the residue out with hot water after sucking up the thin black layer with a baster to remove the majority of it, swis experienced the usual eye and nose irritation as the iodine sublimed out of the container and the water etc...

so swis tried the boiling bubbling thingy with this oily shiot, but this was frustrating. the residual water distilled across first, and then some kind of oily stuff which didn't seem to be incompatible with the vinyl hosing started coming across.

One more incident of suckback made swis give up on this bubbling/sublimation nonsense and got a nice big capacity vacuum flask (from the charity second hand shop, old tin thing with a very wide mouth) filled it with ice and put a small earlenmeyer flask in it and just let the vapours go into that.

anyways, after some deliberation, swis decided that whatever the stuff that was dissolving the iodine must have been some kind of fatty acid stuff (it kinda smelled like burnt vegetable oil) and that for some reason this stuff would continute to occlude the iodine and be nasty and bump (bumping causes suckback in the bubbling through sublimation, i think it should only be used maybe as a resublimation method, when you know you're not going to have to wait for untold liquid to distill across)

so, rather than do that, swis added a load of sodium hydroxide to that mass, some water, some heat, stirring... swiss the silly fool tried to scrape the crud of the bottom of the flask but with his bodgy bent wire rod and how hot the little 250ml flask was a section was taken out of the side of the flask... swis cast another broken piece of glass in the trash and more or less finished up, the evening was over.

the end result is that swis filtered this basified iodo crap and a nice clear yellow/reddish liquid which boiled down to start precipitating crystals of sodium iodide and friends

Os: so adding base to the iodine makes it into iodides and iodic acids, and this is reversible without using peroxide? then i guess with that liquid one just dumps some HCl into it and voila?

cool, nice to know.. this means dont' have to use the peroxide in the extraction from the iodine shampoos.

So, here's my little story, for everyone else who has noticed they don't sell the 500ml bottles anymore and look at you weird for buying two bottles.

the vet shop girl who serves you gives you the bottle in a plastic bag with a nice warm smile and you go home feeling so much better :D
 
 
 
 
    elfspice
(Newbee)
03-24-04 22:31
No 497089
      d'oh     

swis can't remember now *exactly* what he did... thinking about it now, what would happen if one added a strong acid to a solution of potassium/fatty acid salts - i would think that would steal all the potassium and leave you with two layers. thing is, what kind of vegetable or animal oil is more dense than water? or was this just a factor of having what i estimate to be 9g of iodine (very dense) in it... then again i don't know what you get if you dissociate sodium lauryl suphate either or any other synthetic detergent.

I don't remember putting acid in before cooking it up so i think that it may have just been the salt that did it. sodium chloride does have a pKa of 6.5 or something like that, maybe that was enough. I know that soap precipitates from insolubility sink, but if the oil is dissociated via acid it goes to the top.

The bottle said that it was a 'low foaming' detergent in the formula, so maybe the oil i was distilling was turkey red, sulphonated castor oil, which i know conditions textiles in preparation for dyeing, and softens hair. the shampoo is supposed to be to condition the coat and eliminate skin conditions, and the skin conditions are fixed by iodine so the special soap must be the conditioner.