Talk:Potassium ferrocyanide

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I beleieve there is an error concerning "ferroxyl indicator solution". One of two facts are possibly wrong:

 1. That ferroxyl indicator solution contains both potassium ferrocyanide   
 and phenolphthalein, or 
 2. ferroxyl indicator solution turns blue in the precence of Fe+2 ions.  

1. It could possibly be that it contains potassium ferricyanide instead of ferrocyanide, because the potassium ferrocyanide already contains Fe⁺² ions. These ferrous (Iron(II) Fe⁺²) ions should therefore be selfdetecting.

2. Or possibly the ferroxyl indicator solution actually indicates the presence of ferric (Iron(III) Fe⁺³) ions when it turns blue.

I believe that the latter is correct because if the indicator can detect the presence of rust it detects ferric ions. Rust is iron oxide, Fe₂O₃, thus seen as (Fe⁺³)₂(O^-2)₃ OR [Fe₂]⁺⁶[O₃]^-6 with the respective net and gross equivalent ionic charges.

In conclusion I beleive that ferroxyl indicator solution actually contains both potassium ferrocyanide and phenolphthalein, however it is an indicator for Fe⁺³ (ferric Iron(III)) ions.

I would agree, and I have edited the article accordingly: I will try to find a reference to be sure. Physchim62 (talk) 08:03, 23 February 2006 (UTC)

Your fist conclusion is actually the correct one. Ferroxyl indicator contains potassium ferricyanide (AKA potassium hexacyanoferrate(III), which turns blue in the presence of Fe²⁺ ions. I am going to move the paragraph reffering to the ferroxyl indicator to the potassium ferricyanide article. --Ngunn 22:45, 20 September 2006 (UTC)