F.4 Chem pls help 20點!!!
I know that when an iron nail is put in rust indicator, the area near the two ends of the nail is blue because of iron(ll) ions, and the middle part is pink because of hydroxide
ions. But why the pink colour only appears in middle? The iron(ll) ions and electrons
are formed at the two ends. Why the electrons don't react with oxygen and water to
form hydroxide ions at the two ends but only in the middle part?
- 7 years agoFavorite Answer
At both ends, the iron structure is sharp and strained and easily loses electrons (anode) while in the middle, the structure is more intact and organised that electron accumulates there to form the cathode.
If you bend an iron wire or nail, the point of bending is strained and easily oxidized.