[zilalti]

At the moment I am currently trying to make a substantial amount i.e. 25g of fe2o3 for various experiments. So far I found the easiest/cheapest way was to oxidise iron nails in house hold bleach. Recently however I came across some old KNO3 and wondered if I were to make a kno3 solution, would this be a more efficient way of oxidation?

[Will]

You could just try rusting the nails (I have no idea whether the KNO₃ method will work- no harm in testing it). Try heating the nails in an acidified NaCl solution, which should accelerate the rusting. You will want as much oxygen dissolved in the water as possible, so you may want to stir up the solution a lot or think of another method.

If you managed to get a Fe³⁺ solution out of the nails then you could just add OH^-, CO₃^2- or HCO₃^-.

[zilalti]

Thanks I will give the NaCl method ago but i'd rather find out about kno3 solution before I use it as I am a bit too poor at the moment to waste my last few grams.

Also I don't really understand what you mean by Fe2+ ions. I would have thought that could only occur if the Fe2o3 disscoited but I wouln't have thought that would be the case and wouldn't adding OH ions give Iron Hydroxide?

[Will]

Also I don't really understand what you mean by Fe2+ ions. I would have thought that could only occur if the Fe2o3 disscoited but I wouln't have thought that would be the case and wouldn't adding OH ions give Iron Hydroxide?

I meant if you managed to get a Fe³⁺_(aq) solution from your nails (eg adding acid and oxidising) then you could add hydroxide ions (eg NaOH) which would give you Fe₂O₃ (as Fe(OH)₃ doesn't exist - only the iron(II) hydroxide exists).

If I were you, I'd wait for someone else to give you advice on the KNO₃. If you do end up losing/wasting some of your precious iron you could go looking around for some rust (Fe₂O₃) somewhere or 'borrow' some Fe nails (or other iron stuff) from somewhere!

[zilalti]

Ah ok thanks

[hmx9123]

You may be able to accelerate the process by adding some household hydrogen peroxide to the solution as well.