Will a nail rust if placed in these conditions...?

a) Tap water


b) Salt water


c) If submerged in boiled water with a layer of oil over the water.Will a nail rust if placed in these conditions...?
a) Yes but this will rust the slower than b.





b) Yes this will rust the fastest because of the salt which speeds up the corrosion of the metal.





c) Eventually it will as all things rust but the oil provides a protective layer for the time being.Will a nail rust if placed in these conditions...?
To rust iron needs both water and oxygen.





(a) has both water and oxygen;


(b) has water, oxygen and ions in the solution...which will make the process even quicker.


(c) has water, but, if the water is thoroughly boiled and then covered in oil (to slow down the reabsorption of air) this will not rust (well, not very quickly!!) as there is no oxygen in the water.
conditions for nail to rust is presences of air and water


2H2O + 2O2 + 4e → 4OH-


Fe → Fe2+ 2e


2Fe + 2H2O + 2O2 → 2Fe2+ +4OH- → 2Fe(OH)2 {rust}





a) yes


b) yes


c) no, because oil doesn't allow air enter thus rusting does not occur
the nail will rust in all three cases because corrosion will take place. which means that the iron molecules will combine with the oxygen molecules to give you iron oxide or rust.
an iron nail willnnot rust in any of these conditions since for undergoing corroision metal should be in different environment, partilly dipped with different concentration of oxygen.