[metalriffzz]

I finally found out something that will get rid of those pesky Manganese dioxide stains, you know the ones you get from leaving potassium permanganate out on concrete etc... Anyway it's 1 part vinegar and 1 part store bought hydrogen peroxide. I was just wondering if anybody knew the exact reaction taking place.

[Borek]

I know it sounds funny - peroxide gets oxidized

[xiankai]

the manganese dioxide is converted to Mn2+ ions which are colourless

[metalriffzz]

If thats the case, what makes the MnO2 soluble in that solution, but not soluble in the vinegar or the peroxide by itself?

[Borek]

You need peroxide and H⁺ for this reaction to take place.

[metalriffzz]

Ohh, ok thanks. So I'm guessing this reaction would be more efficient with say, HCl?

[constant thinker]

Do you suppose those kinds of stains would appear on a bath tub. I have some brownish stains on my tub where the water runs around the drain and Bleach couldn't get rid of it. I was guessing it was maybe Iron but I thought that Bleach would probably remove of the problem.

If it's possible that this stuff can be Manganese then the vinegar trick should work right?

[Borek]

I have some brownish stains on my tub where the water runs around the drain and Bleach couldn't get rid of it. I was guessing it was maybe Iron but I thought that Bleach would probably remove of the problem.

No way.Bleach may - at best - try to oxidize iron more. But iron in such stains is already at +3, so the bleach can't do anything.

If it's possible that this stuff can be Manganese then the vinegar trick should work right?

Have you poured some manganese solution there? If not, these are not manganese stains.

Try some iron stain and lime remover, it should do the trick.

[Borek]

Ohh, ok thanks. So I'm guessing this reaction would be more efficient with say, HCl?

Probably, although HCl is not the best choice, as in the presence of oxidizers Cl^- can get oxidized to Cl₂. I am not sure potentials of the oxidizers in this case will be high enough, but acetic acid or H₂SO₄ look like much safer selection.