Iodine Synthesis

[encipher]

Hi,

 

So I ran out of Iodine, and I was attempting to make myself some. I took some NaI, dissolved it in distilled water, then added H2SO4 and H2O2. Iodine was made successfully, but the issue im having is isolating the iodine, I set up my distillation apparatus, and waited for the vapors to be begin deposition.. unfortunaltey they solidified at the opening of the flask, blocking the way for any other iodine to go through. Does anyone know how to solve this issue? or a different way to do it?

 

Thanks

[woelen]

I did isolate iodine by taking a beaker and putting in the slurry of iodine/water/acid remains. I put a glass plate on top of the beaker and then heated it. The crystals of iodine quickly settle at the glass plate, together with some water droplets.

 

Then I took the iodine with water droplets from the glass plate (and also the walls of the beaker) and mixed this with some conc. H2SO4. This binds the water and then again repeat the procedure. This way, you get rid of most of the water. A third time gives you totally dry iodine. Commercial iodine is triple distilled.

 

Another way of isolating the iodine is dissolving it in some solvent (e.g. low-boiling ligroin) in which water does not dissolve. I'm not sure though how well iodine dissolves in the ligroin. A better solvent would be CS2, but that is very toxic, very stinky and not easy to obtain. It also adds some impurity to the iodine. I myself did not try the extraction procedure. The distillation procedure worked fairly well for me.

[encipher]

Thanks, I'll give that a shot then.

[jdurg]

It's a good idea to keep the entire apparatus quite warm, and the only cool part should be where you want the I2 crystals to solidify.

[YT2095]

Ice on the top of the glass or condenser plate is a good idea too