Swim's pal is really pist, he ordered a gallon of 7% tincture which also contained 5% potassium iodide.

He mixed it with a gallon of cold water, 1/2 gal of bleach and a cup of battery refill sulfuric. At first it looked like hundreds of grams in there but eventualy disolved only leaving about 5grams to be filtered.

Obviously he added too much oxidizer and not enough sulfuric since the acid used to fill batteries is watered down all to hell but its to late he already dumped everything in the local nature reserve.

Can someone explain in chem terms what happens during a i2 precip and how this fuckup could have been fixed?

This is a good question, and I don't think I've ever seen it posted before. I'd like to know the answer myself...*bump*

Use more pure distilled water, it should be more than 1 to 1. And you didn't add too much oxidizer, but you should use some 30% peroxide in place of some of the bleach.

What is happening is that the oxidizers are turning the iodide into iodine. This makes the iodine less soluble and some crashes out. BUT you must add lots of water because tincture is IPA water mixture and this dissolves iodine well. If you dilute it enough so it is mostly water the iodine crashes out.

So for a gallon of tincture you should do it a liter at a time unless you want to do it in a five gallon pail.

There is definitely a steep gradient present when using bleach and sulfuric. SWIM only uses this method when recovering iodine from post rxn fluid. This is because of the extreme alkalinity that must be overcome.

From observation, it seems that this method is more tolerable of a highly acidic environment than hcl and H2O2. The problem is, there is a fine line between enough bleach to make the iodine completely fall out and adding too much and the whole thing going straight to clear yellow.

I believe it is video editor who came up with a new twist on the H2SO4\bleach method, but his method produces a small but potentially lethal quantity of poisonous gas. It works quite well after you get the hang of it.

When it comes to tincture in known concentration, nothing works better than hcl and H2O2 in this part of the world. Even with crummy old 2%.

Tryptamine you didnt mention anything about the acid?

Yes I know the iodide gets oxadized to iodine but why would it require any peroxide when useing bleach???

And when you add too much oxadizer the precipitated iodine disappears, why? What is happining? How can it be preciped after adding too much oxadizer?

What does the acid do?

Patience is a virtue....right kirb?