[10分]關於rusting

Rusting refers to the corrosion of iron.
It occurs in the presence of oxygen and water. The rust is hydrated iron (III) oxide.
( 1 ) Rusting can be speeded up by sodium chloride solution becuase it forms a conducting solution with water.
Then, iron loses electrons more readily to form hydrated iron (III) oxide ( rust ).
( 2 ) Rusting can be speeded up by sulphur dioxide because it dissolves in rain water to give acid rain.
Since acid contains mobile ions , it also forms a conducting solution.
Therefore, iron loses electrons more readily to form hydrated iron (III) oxide ( rust ).

2008-01-30 16:22:20 補充：
下面ge都冇完全答到條問題, e+係問點解會speed up rusting, 你只係答咗ionic substance同acidic solution而miss咗forms a conducting solution~~~