A 38 g sample of iron ore is treated as follows.
The iron in the sample is all converted by
a series of chemical reactions to Fe2O3. The
mass of Fe2O3 is measured to be 11.1 g. What
was the mass of iron in the sample of ore?
Answer in units of g
Another stoichiometry problem BUT there is a short cut that saves a lot of time; however, the shortcut is not taught, to my knowledge, anymore.
Here is the short cut.
grams Fe in the ore = grams Fe2O3 x (2*atomic mass Fe/molar mass Fe2O3) = ?