Ferric Chloride colour

[rvdzero]

hey all! i made some ferric chloride the other day and it was a nice vibrant greeny yellow colour, but over time it had turned brownish. It is stored in a jar. Would the stuff in the jar still be ferric chloride? Thanks, rick

[YT2095]

ferric chloride is an orange/brown color when it`s hydrolised, and since it`s a deliquescent compound it can rip moisture from the air and hydrolise itself.

[rvdzero]

Ah sweet as, thank you very much!

[Tartaglia]

The green is ferrous chloride (FeCl2) the orange ferric chloride (FeCl3)

[YT2095]

AND it`s also possible to have a mixture of the 2 as well, depending on which was in excess.

[CharonY]

Yup. Sounds like a significant amount of it has oxidized. The pH should be low enough that for the most part it should be ferric chloride (at higher pH some other iron (hydr-)oxides may form.

[hermanntrude]

If you want to keep it reduced, keep it in some pure water with some iron filings or iron wool in it.

[John Cuthber]

This stuff was meant to be the oxidised form. It hasn't oxidised.

 

Adding steel wool would turn it into something else.

 

It has, as was pointed out earlier, picked up watter (possibly lost HCl too) and hydrolysed.

In solution FeCl3 is greenish yellow (usually with a brown sludge at the bottom) This is the colour of the FeCl4- ion.

[CharonY]

Actually I am pretty sure that FeCl3 in aquous solution is reddish-brown. At least it was in my memory.

[CaptainPanic]

In a table in an old book I got since highschool it says that [ce] FeCl3.6H2O_{(s)} [/ce] is red-brown.

[YT2095]

the stuff I have here goes the same color when added to water only it`s more of an orange/brown to my eyes (stated in post #2), the Crystals however are a mustard yellow.

[CharonY]

Yes, the more mustad-like one should be the anhydrous form. I just recalled that it appears greenish under reflected light.