Question

What is the mass of each ore in atomic mass units?
Hematite Fe2O3

pyrite FeS2

Answer 1

Fe₂O₃: 2*M(Fe) + 3*M(O) = 2* 56 a.m.u. + 3* 16 a.m.u. = 160 a.m.u.
FeS₂: M(Fe) + 2*M(S) = 56 a.m.u. + 2* 32 a.m.u. = 120 a.m.u.