Strange result for practical (1 Viewer)

[pasta8]

I have an experiment where magnesium is wrapped around a nail and placed in a petri dish filled with agar/saltwater and indicators to locate anode and cathode. The nail does not corrode beacuse its oxidation reaction has been stifled. Only query is: a white substance has formed around the magnesium on the nail. Magnesium oxide possibly? anyways, what is it, and why is it there? how is this combatted in industrial Mg anodes?

 

[EViL.GENiUS]

Hi

I think its probably magnesium hydroxide.

 

[Michaelmoo]

Yep. I think itd be magnesium Hydroxide. My guess is that the experiment has been set up for some time?

Magnesium is a pretty reactive metal as you know. Although, it is also a self-passivating metal, thus the outer oxide layer neutralises its reactivity. But it seems as though somehow, the agar/saltwater has disintegrated its outer oxide layer, so it readily reacts with hydroxide ions in water.