Sciencemadness Discussion Board

Lugol's Solution

Traveller - 13-10-2012 at 23:45

Is this guy making Lugol's Solution in a kind of backwards way?

http://www.youtube.com/watch?v=CLhwkFKLdPA

Vargouille - 14-10-2012 at 01:22

Short answer, no.

Lugol's solution is a mixture of iodine and an iodide salt. This process is a simple oxidation of iodide by acidified hydrogen peroxide, which converts almost all of the iodide into iodine, with little to no production of triiodide. One could argue that because of the lack of precise measurements on the amount of reagents used, some triiodide may be produced if the amount of iodide salt is in excess, however, the main product is free iodine, which precipitates and is removed. The dark color of the solution remaining is, I believe, from the small amount of iodine that is soluble in water, rather than a concentrated solution of potassium triiodide.

Traveller - 14-10-2012 at 11:21

So, if the solution he ends up with is free iodine, what would happen if he then added more potassium iodode powder to this mix?

blogfast25 - 14-10-2012 at 11:29

This belongs in the other Lugol thread by the same thread starter.

Traveller - 14-10-2012 at 11:44

I'll move it over there now. Is there a way of deleting this thread?

Traveller - 14-10-2012 at 11:55

I've transferred the contents of this thread to my other thread "Leaching Gold with Lugol's Solution and Recycling Lugol's Solution". Please post any responses there.

[Edited on 14-10-2012 by Traveller]