JAMB - Chemistry (2007 - No. 6)
The reddish-brown rust on iron roofing sheets consists of
Fe3+(H2O)6
FeO.H2O
Fe2O3.3H2O
Fe3O4.2H2O
Explicació
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.