corrosion (1 Viewer)

[tamia]

i recently conducted an experiment to see whether zinc would corrode when placed in salt water, but it didn't. Any reason why this didn't happen? i thought zinc was a fairly reactive metal?

 

[grimreaper]

I'm guessing it forms an impervious oxide layer which prevents corrosion. You'll probably have noticed it's lost its luster while in the water (if it didnt have an oxide layer before)

 

[Xayma]

Did you fully place it in salt water? If it is fully submerged then you want form the anodic and cathodic regions (except along the grain boundries but that is more stress boundries).

When it is partly submerged then the lower oxygen zone will become anodic, and the higher oxygen zone cathodic (this is what causes corrosion around rivets etc as moisture gets in and shuts off oxygen).

 

[TheKing]

zinc is a passivating metal....
i think

 

[xiao1985]

zinc is slightly passivating...

but i think it mostly is due to the oxide layer formed without or with minimal presence of water... ie, it oxides in hair, with out trapped water molecules in it... hence the rust...

and when it is submerged in salt water, the electrons cannot pass the oxide layer, hence it is nto reacting...