2. 菜刀上沾有食盐水后,置于空气中一段时间会生锈,其原理是 ( )
|
|
正极 |
负极 |
|
A |
Fe-2e = Fe2+ |
2H2O+O2+4e = 4OH- |
|
B |
2H++2e = H2 |
Fe-2e = Fe2+ |
|
C |
2H2O+O2+4e = 4OH- |
Fe-3e = Fe3+ |
|
D |
2H2O+O2+4e = 4OH- |
Fe-2e = Fe2+ |