[stagbeetle]

I would not use livestrong as a source.

If the pictures are true to the situation, the concentrations are tiny. You can look up videos of people putting less than a teaspoon into water to get the same result.

IIRC, PP can be a precursor to chlorine. But, you're comparing two different chemicals here and what applies to one likely doesn't apply to another.

There is a chance your skin will feel like it's burning if it's not fully dissolved in water. I wouldn't advise touching the dry powder. The shards will embed into your skin and it will feel like an open wound filled with Tabasco for a long time.

Fun-fact: If you mix it with glycerol it combusts, so don't use any lotions with it if you get some on your skin.

ETA: I don't know what's going on, but there's a lot of low-effort responses in this thread. Is it the hours?

[jcranmer]

> IIRC, PP can be a precursor to chlorine.

Converting KMnO₄ to Cl¯ would require a nuclear reaction. Chlorides are generally soluble, so it's not going to cause an insoluble salt to slowly dissolve as a permanganate salt precipitates instead. It does appear to be a stronger oxidizing agent than Cl₂ (and Cl¯ and ClO¯ and ClO₂¯), but there are likely better reducing agents in most water than dissolved chlorine ions.

[zzazzdsa]

For what it's worth, permanganate is an extremely strong oxidizer (probably the second strongest stable solid oxidant known, after persulfate), but at neutral pH it is unable to oxidize chloride to hypochlorite and beyond. (The electrode potentials are too close, and anyways the maganese dioxide byproduct turns hypochlorite to chloride and oxygen.) Instead of reacting with a reducing agent in water, (the main possibilities are simple organics and ferrous iron, and these turn to carbon dioxide or insoluble ferric oxide [sidenote: this is why permanganate is added to water in the first place]) permanganate tends to break down to oxygen and manganese dioxide, which settles out.

[stagbeetle]

My wording was vague, you'll have to excuse me.

[mulmen]

I wish I knew enough about chemistry to know if you are providing valuable commentary or pulling our collective leg. I will give you the benefit of the doubt.

[throwaway2048]

>IIRC, PP can be a precursor to chlorine

potassium permanganate does not contain chlorine

[stagbeetle]

No, but muriatic acid does. I'm pretty sure it's a redox reaction.

[lqdc13]

How is HCl related to KMnO4? And why would one combine them?

Why not just add a hypochlorite to water if the end goal is to disinfect with chlorine?

[jcranmer]

The allegation is that KMnO₄ is undergoing a redox reaction with HCl to produce Cl₂ gas (which is a plausible redox reaction, given the half-reaction potentials).

But yeah, in practice you're going to disinfect with Cl₂ gas or NaClO. The water plant I worked at switched from Cl₂ to ClO¯ as primary disinfectant, and the operators were all for it. No more need to manually switch out Cl₂ tanks, no more Cl₂ venting issues (spilling NaClO is nowhere near as bad a Cl₂ leak). (The plant also used O₃ for bonus disinfection as well. The operators hated it at first, but now would throw a conniption fit were it broken).

[stagbeetle]

It was a comparison on par with the parent comment's argument. Looking back, it wasn't well constructed on my end and probably led to confusion.

What I was going for was: just because they do the same thing doesn't mean they're the same at all.

HCl + KMnO4 -> KCl + MnCl2 + Cl2 + H2O