Tin-iron cans question
2013-03-11 5:01 am
I want to ask,why iron corrode faster when a tin can is scratched?As I know, iron is above Sn in e.m.f series.However, would Sn become ionized in air? I don't think so because Sn is quite unreactive metal (plz correct me if I am wrong) and hence the corrosion rate of iron should be the same as that in normal condition. PLZ help!
回答 (2)
2013-03-13 5:30 am
✔ 最佳答案
um... yes and no.. but your conclusion is wrong.First, you hv to know that rust is Fe ion reacting with air+water.
you are right that Sn is less reactive (,more stable) than Fe. If a metal is more stable, it is more likely that it will gain electrons to inhibit itself from becoming Sn2- ions, right? So where does those electrons come from? They come from nearby surroundings--- from iron~ So iron loses electrons more readily. When it loses electrons, it becomes Fe ion, which will react with air+water to corrode. Therefore, the corrosion rate is higher :). Get it? :)) reply or message me if its unclear~
2013-03-12 21:36:23 補充：
ahh~ u r correct that Sn will not easily ionize in air (comparitively)~ because there are supplies of electrons from Fe :D
參考: me~
2013-03-13 9:08 pm
To 演曈:
you say"it is more likely that it will gain electrons to inhibit itself from becoming Sn2- ions"
Sn is metal and it should lose electrons to be Sn2+ ions instead?
you say"it is more likely that it will gain electrons to inhibit itself from becoming Sn2- ions"
Sn is metal and it should lose electrons to be Sn2+ ions instead?
收錄日期: 2021-05-01 16:52:47
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