[tex]\displaystyle{ M_{Fe_{2}O_{3}} = 2 \cdot A_{Fe} + 3 \cdot A_{O} }[/tex]
[tex]\displaystyle{ A_{Fe} = 56 \ ; \ A_{O} = 16 }[/tex]
M = 2 × 56 + 3 × 16
M = 112 + 48
M = 160 g/mol
