Farmerism said:
hm yeah i guess so. but now im confused about another thing.
with reference to galvanising. um.. is what i have to say below true?
zinc is more readilly oxidised than iron. since zinc is being used to protect the iron from corrosion (which is what happens when the iron oxidses), when it is scratched ...........
no wait im confused here. when iron 'corrodes' isnt it accepting electrons? ..... because Fe^2+ + 2e -> Fe...
no wait.. when iron corrodes it should be Fe -> Fe^2+ + 2e because Fe ions break off the crystal lattice and become Fe^2+?....
can anyone see where my problem is.. im confused about whats oxidised and whats reduced in the galvanising protection thing....
the above was just my thinking process. hope it didnt make anyone dumber
Zinc acts as the sacrificial anode which is the metal which protects iron from being oxidised.
When iron
corrodes it is being oxidised so it
loses electrons which is called the anodic site, and where reduction occurs is called the cathodic site.
So:
Fe
2+ ---> Fe
(s)+2e
-
Some impurities such as carbon, where these electrons can flow, where carbon can act as a cathode if present. The oxygen dissolved in where the water touches the metal is where reduction occurs