Sciencemadness Discussion Board
Not logged in [Login - Register]
Go To Bottom

Printable Version  
 Pages:  1  2
Author: Subject: Cheap Potassium Iodide
Deathunter88
National Hazard
****




Posts: 371
Registered: 20-2-2015
Location: Beijing, China
Member Is Offline

Mood: No Mood

[*] posted on 26-11-2018 at 23:17


What's the average price of KI in the USA? I fail to see how $6 for a mere 100g is cheap. Here in China 500g of reagent grade KI is only $10 or so, and even a brand name is $20 for 500g, so I don't really see the incentive to sell fake KI, especially at such a high price.
View user's profile View All Posts By User
Mr. Rogers
Hazard to Others
***




Posts: 179
Registered: 30-10-2017
Location: Ammonia Avenue
Member Is Offline

Mood: No Mood

[*] posted on 27-11-2018 at 00:06


I bought 300g from the OP's link and, as someone stated, it was slightly wet but it's definitely KI.

It was shipped in a leaking plastic bag inside an envelope and the customs form said it was a necklace.

I think it's "fine" for the price.




[Edited on 27-11-2018 by Mr. Rogers]
View user's profile View All Posts By User
Mr. Rogers
Hazard to Others
***




Posts: 179
Registered: 30-10-2017
Location: Ammonia Avenue
Member Is Offline

Mood: No Mood

[*] posted on 27-11-2018 at 00:14


Quote: Originally posted by Deathunter88  
What's the average price of KI in the USA? I fail to see how $6 for a mere 100g is cheap. Here in China 500g of reagent grade KI is only $10 or so, and even a brand name is $20 for 500g, so I don't really see the incentive to sell fake KI, especially at such a high price.


It's much more expensive in the US - probably 4-5x as much. Dunno why.
View user's profile View All Posts By User
woelen
Super Administrator
*********




Posts: 6773
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 27-11-2018 at 00:14


Average price where I live (EU) is appr. EUR 20 per 100 gram, so $6 (appr. EUR 5) per 100 gram is very cheap for us. Prices in the USA will not be very different.



The art of wondering makes life worth living...
Want to wonder? Look at http://www.oelen.net/science
View user's profile Visit user's homepage View All Posts By User
Ubya
International Hazard
*****




Posts: 620
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline

Mood: I'm a maddo scientisto!!!

[*] posted on 27-11-2018 at 01:07


Quote: Originally posted by Deathunter88  
What's the average price of KI in the USA? I fail to see how $6 for a mere 100g is cheap. Here in China 500g of reagent grade KI is only $10 or so, and even a brand name is $20 for 500g, so I don't really see the incentive to sell fake KI, especially at such a high price.


if you can find a source that would sell internationally KI for that price we would be really happy:D





---------------------------------------------------------------------
feel free to correct my grammar, or any mistakes i make
---------------------------------------------------------------------
View user's profile View All Posts By User
DavidJR
International Hazard
*****




Posts: 655
Registered: 1-1-2018
Location: Scotland
Member Is Offline

Mood: Anxious

[*] posted on 27-11-2018 at 08:19


Quote: Originally posted by Deathunter88  
What's the average price of KI in the USA? I fail to see how $6 for a mere 100g is cheap. Here in China 500g of reagent grade KI is only $10 or so, and even a brand name is $20 for 500g, so I don't really see the incentive to sell fake KI, especially at such a high price.


I just looked at one of my suppliers in the UK and they have KI for £11.25/100g and NaI for £26/100g.

$6 US is about £4.70 at the moment. So yes, if it wasn't a scam, this would be very cheap for me.
View user's profile View All Posts By User
S.C. Wack
bibliomaster
*****




Posts: 1958
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline

Mood: Enhanced

[*] posted on 27-11-2018 at 15:51


Quote: Originally posted by Deathunter88  
What's the average price of KI in the USA? I fail to see how $6 for a mere 100g is cheap. Here in China 500g of reagent grade KI is only $10 or so, and even a brand name is $20 for 500g, so I don't really see the incentive to sell fake KI, especially at such a high price.


A price beyond competitive on amazon is $85/kg...best is $56/kg, for 5, which makes me wish I needed that much, that's insanely low. These are just repackers of probably Chinese goods. There are sellers of I, 50 g. for $10; technically, to import legally one needs a license from the DEA, which they won't provide.

Someone who has been pricing chemicals for a time might be suspicious of cheap imported iodide, and would want to test it well. Does China control some vast natural source of iodide? I suspect that the price from a non-Chinese source is higher than the amounts given above.

[Edited on 28-11-2018 by S.C. Wack]




"You're going to be all right, kid...Everything's under control." Yossarian, to Snowden
View user's profile Visit user's homepage View All Posts By User
Sulaiman
International Hazard
*****




Posts: 2463
Registered: 8-2-2015
Location: Shah Alam, Malaysia
Member Is Online


[*] posted on 6-12-2018 at 04:46


With the recently purchased potassium iodide I tried to precipitate the iodine using hydrogen peroxide and got an indication of low iodine content.

Today I made up a 500ml solution of what should be a 1.0M solution of the suspect potassium iodide,
(which I bought via eBay seller 94racing-au, the cheapest at the time)
and bubbled chlorine gas through 100ml of the solution
to replace the iodide with chloride and precipitate iodine.

36% HCl in a 3ml disposable pipette, TCCA in a side-arm test tube.
Cl2_KI.jpg - 1.5MB

The crop of wet iodine on a 90mm diameter filter paper.
WetIodine.jpg - 2.5MB

Ideally there should be 1/10th mole of iodine = 12.7 g
A little was lost to physical handling, and there should be a little Iodine in the filtrate/solution.
I guess that potassium chloride may increase the solubility of iodine in a manner similar to potassium iodide ?
Could anyone please tell me, or point to, or calculate,
the solubility of iodine in 1.0M Potassium Chloride ?
especially in the 10 to 20 Celcius range.

Result : 8.05g dry iodine

The filtrate has a strong yellow tint and the tissues used beneath the filter paper absorbed a lot of iodine giving a strong blue tint,
so I still suspect that KCl increases the solubilit of iodine in water..
Although the yield was only 63% I suspect that the KI was pure.
now I need to do a titration to be sure.

[Edited on 6-12-2018 by Sulaiman]




CAUTION : Hobby Chemist, not Professional or even Amateur
View user's profile View All Posts By User
DavidJR
International Hazard
*****




Posts: 655
Registered: 1-1-2018
Location: Scotland
Member Is Offline

Mood: Anxious

[*] posted on 6-12-2018 at 05:22


I just got a refund for my fake stuff.
View user's profile View All Posts By User
Ubya
International Hazard
*****




Posts: 620
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline

Mood: I'm a maddo scientisto!!!

[*] posted on 6-12-2018 at 12:35


Quote: Originally posted by Sulaiman  

I guess that potassium chloride may increase the solubility of iodine in a manner similar to potassium iodide ?


iodine is solubile in iodide solution because it forms triiodide, which is soluble





---------------------------------------------------------------------
feel free to correct my grammar, or any mistakes i make
---------------------------------------------------------------------
View user's profile View All Posts By User
S.C. Wack
bibliomaster
*****




Posts: 1958
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline

Mood: Enhanced

[*] posted on 6-12-2018 at 15:38


Quote: Originally posted by Sulaiman  
I guess that potassium chloride may increase the solubility of iodine in a manner similar to potassium iodide ?
Could anyone please tell me, or point to, or calculate,
the solubility of iodine in 1.0M Potassium Chloride ?
especially in the 10 to 20 Celcius range.


You have the iodine, KCl is hopefully not a challenge...

So I looked in Mellor and he gives the exact answer actually and it's a good thing, because CA abstracts the same article but doesn't provide details...just like the publisher of Gmelin's didn't provide a pdf of any I volume for sale last time I looked...if you believe 1920 Gazz It, KCl accounts for less than 1/10 gram of the missing I.

[Edited on 6-12-2018 by S.C. Wack]




"You're going to be all right, kid...Everything's under control." Yossarian, to Snowden
View user's profile Visit user's homepage View All Posts By User
Sulaiman
International Hazard
*****




Posts: 2463
Registered: 8-2-2015
Location: Shah Alam, Malaysia
Member Is Online


[*] posted on 6-12-2018 at 16:41


Actually I would have to buy or make some KCl so the data is useful, thanks.
I dowloaded Mellor years ago but forgot the contents :(

After tidying up I dropped a pinch of TCCA into the filtrate,
I'll check for any precipitate tomorrow.

To be sure I'll boil dry the filtrate to dryness then heat the residue to see how much iodine vapour is produced.

I just realised that the iodine may have precipitated in particles too small to be caught by the medium filter paper that I used,
which now seems more likely than dissolution carrying the iodine into the tissues used beneath the paper for drying the iodine,
but if true then the light yellow colour of the filtrate should be much darker.
I'm confused.




CAUTION : Hobby Chemist, not Professional or even Amateur
View user's profile View All Posts By User
S.C. Wack
bibliomaster
*****




Posts: 1958
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline

Mood: Enhanced

[*] posted on 6-12-2018 at 19:26


The thinking was neutralizing HCl and K (bi)carbonate or hydroxide exactly should be a low hurdle.

IIRC H2O2/HCl and KI is popular enough that there were calculators for the different parameters, for meth cooks, who seemed satisfied. Perhaps with Cl as a gas, bad things are more likely to happen?




"You're going to be all right, kid...Everything's under control." Yossarian, to Snowden
View user's profile Visit user's homepage View All Posts By User
MrHomeScientist
International Hazard
*****




Posts: 1745
Registered: 24-10-2010
Location: Flerovium
Member Is Offline

Mood: No Mood

[*] posted on 7-12-2018 at 10:22


I know for bromine it can form interhalogens with chlorine; that's why I avoided Cl when I made my Br. I wonder if something similar can happen with iodine.
View user's profile Visit user's homepage View All Posts By User
UC235
National Hazard
****




Posts: 442
Registered: 28-12-2014
Member Is Offline

Mood: No Mood

[*] posted on 7-12-2018 at 11:02


Quote: Originally posted by MrHomeScientist  
I know for bromine it can form interhalogens with chlorine; that's why I avoided Cl when I made my Br. I wonder if something similar can happen with iodine.


ICl and ICl3 are well known. Bubbling Cl2 through iodide solution is how woelen made periodate.
View user's profile View All Posts By User
 Pages:  1  2

  Go To Top