Are there other fluids that dont include water that cause rusting.?

Question

I am looking for NON WATER environments where rusting could occur..

and whether you could rust with CHLORINE gas instead of oxygen..

I was just curious what is absolutely necessary for rust to occur

pisgahchemist · Accepted Answer

Rust is FeO(OH).  In nature, it is the mineral goethite.  Under water rust is Fe(OH)3. In extreme environments where rust is dehydrated, Fe2O3 results. The formation of rust ALWAYS requires water.

There are many reactions which involve the oxidation of iron as when reacting with chlorine, as Jon suggests, but these reactions do not produce rust.

Jon suggests that water is the oxidizing agent.  Oxygen is the oxidizing agent, not water.  But water is necessary for the product to be called "rust."

4Fe(s) + 3O2(g) + 2H2O(l) --> 4FeO(OH)(s) ......... formation of rust

Jon · Answer

This comes down to definition.

'Rust' usually means oxidisation: by that definition water is the main room temperature liquid causing rust.

If you treat rust as meaning any chemical attack,  then chlorine is also capable of attacking iron. However it usually occurs as a gas not as a liquid.

Roger the Mole · Answer

No.  Water is always required to cause rusting.

Are there other fluids that dont include water that cause rusting.?

3 Answers