[sam]

why salts make metal oxidized more easily?

[sam]

i have one more question   
why salting of roads during the winter increases the corrosions of  cars ?

is this because

salts make metal oxidized more easily?

[Borek]

Oxidation requires charge transfer, charge transfer is easier and faster in the solution of higher conductance.

[sam]

but i just checked the book , it said the answer is because salt provides an electrolyte.
oh  i think in this case ,its different because the salt is solid not solution,right?

[Borek]

because salt provides an electrolyte.

And electrolyte makes the solution less resistant (increases conductance).

[constant thinker]

"Rusting" is an electrochemical reaction (at least for iron). As Borek said, the salt is an electrolyte which lowers the electrical resistance in the solution. Easier flow of electricity = easier oxidation.

This wiki article may help some. It give you some good chemical formulas. If you still don't understand just ask.