Question

An ore contains Fe3O4 and no other iron. The
iron in a 54.6-gram sample of the ore is all converted by a series of chemical reactions to
Fe2O3. The mass of Fe2O3 is measured to be
21.3 g. What was the mass of Fe3O4 in the
sample of ore?
Answer in units of g

Answer 1

21.3 g Fe2O3 x (2*molar mass Fe3O4)/(3*molar mass Fe2O3)= ?

Answer 2

30.88g