The reddish-brown rust on iron roofing sheets consists of
- Fe3+(H2O)6
- FeO.H2O
-
Fe2O3.3H2O
- Fe3O4.2H2O
The correct answer is: C
Explanation
The chemical formula for rust is Fe\(_2\)O\(_3\).xH\(_2\)O, which represents hydrated iron(III) oxide, where "x" indicates the variable amount of water molecules associated with the iron oxide.