Make Potassium Iodide

If you want to read about this video and how it relates to the recent concerns about radiation in Japan, see the following post on my blog: http://thehomescientist.blogspot.com/2011/03/potassium-iodide-and-radiation.html

Here I make potassium iodide from elemental iodine and potassium hydroxide.

3I2 + 6KOH == 5KI + KIO3 + 3H2O

The coproduct of potassium iodate can be separated easily because it is far less soluble in water, and to ensure it was all precipitated out I immersed the solution in an ice bath.

This video is a good demonstration of how things really go when you do chemistry yourself. You start with a bunch of assumptions, and a lot of the time many of these are proven wrong and you have to figure out another way to do it. For example, the additional heating I had to do and the fact that I used too much iodine. I've added a number of annotations to highlight this as well.

Category:

Science & Technology

Tags:

• iodine
• potassium
• hydroxide
• iodide
• iodate

[robl35771]

I don't think you are extracting all of the KIO3 just by precipitating at cooler temperatures. KIO3 is soluble to an extent in the KI solution itself. I think if you ran an assay on this mixture, you would find a significant portion of KIO3 still in the final crystalline product.

[mrhomescientist]

@robl35771 That's an excellent point, I hadn't noticed that KIO3 becomes more soluble in KI solution. I'll have to think about how to purify this, perhaps a recrystallization? Just another reason why you shouldn't use this for edible radiation protection. Thanks for pointing it out!

[superiorplanet]

do you HAVE t boil the potassium iodide down to get the crystals or can I just leave it?

thanks, loved the video btw, very clear and great explanations :)

[mrhomescientist]

@superiorplanet Thanks! No you don't have to boil it, you could just let it evaporate like I did at the end with the watch glass. It'll form bigger crystals that way too.

[aeroscope]

The color you see is due to the formation is triiodide not iodate!!

[mrhomescientist]

@aeroscope You're right, both of those will be in solution. The color is probably predominantly triiodide, like you said. Good catch!

[adidas4life10]

How close have you come to blowing up your house? I gotta know

[9DragonMaster]

@visionfirst1970 INFOWARS.COM STAY INFORMED, ALEX TOLD US B4 ANYONE!

[KrankieV2]

the one person who disliked this is suffering with chemical burns from the KOH

[Agentoxedo07]

Holy-Terrorist:>*=* Im impressive to look chemistry in right picture video!

[Agentoxedo07]

Holy-Terrorist:>*=* I never maked free chemistry in my house, i haves a parents!

I speak french and little english.

-^=^-

[vmelkon]

@HHHdahman KI is not an element. It is a compound. If you want to buy, there are sellers on ebay. You can also get it from unitednuclear dohth com

[nivk2011]

How much in grams of the potassium iodide did you make?