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Recipe of the Week – Week 20: Ferroxyl Indicator

Continuing our new series of chemical recipes, we bring you week 20 – ferroxyl indicator (K3Fe(CN)6 (aq)).

Remember that when preparing any of our recipes, you should:

  • Always wear appropriate PPE including eye protection and gloves.
  • Always add acid to water (never water to acid).
  • Use a fume cupboard.
  • Always carry out a risk assessment when using any chemicals.
  • Follow all recommended safety procedures and adhere to the label instructions, hazard warnings and local legislations.

What is ferroxyl indicator?

Ferroxyl indicator can be used to show the process of rusting. When iron atoms begin to rust, they lose electrons to form iron ions. Ferroxyl indicator turns blue in the presence of iron ions. This shows that rusting has begun, even if there is no reddish brown rust showing on the surface of the iron. A pink colour is also produced by the ferroxyl indicator. This shows that the ions being lost by iron are being gained by the water and oxygen that are also involved in rusting

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Scan the QR codes for classroom experiments to follow with your safe and prepared ferroxyl indicator.