Rep for all contributers
Why can't potassium hexacyanoferate(III) be used to test for Fe3+? Watch
- Thread Starter
- 25-04-2016 19:47
- Official Rep
- 27-04-2016 21:10
Sorry you've not had any responses about this. Are you sure you've posted in the right place? Here's a link to our subject forum which should help get you more responses if you post there.
You can also find the Exam Thread list for A-levels here and GCSE here.
Just quoting in Puddles the Monkey so she can move the thread if needed
Spoiler:Show(Original post by Puddles the Monkey)
Offline14ReputationRep:Community AssistantStudy Helper
- Community Assistant
- Study Helper
- 28-04-2016 13:42
However, when Fe2+ interacts there is a possibility of charge transfer between the two iron ions in different oxidation states which absorbs energy in the visible region of the spectrum and an intense blue colour is produced.
The same thing happens if hexacyanoferrate(II) reacts with Fe3+ ions.
[Fe(CN)6]3- + Fe2+ --> [FeFe(CN)6]-
[Fe(CN)6]4- + Fe3+ --> [FeFe(CN)6]-
The potassium salt of the compounds used to be called Turnbull's Blue and the other Prussian Blue, but they are chemically identical.Last edited by charco; 28-04-2016 at 13:45.