Fe (iron) = 55.8 grams Fe = 1 mole Fe
2.56 • 10^-3 moles Fe / 1 • 55.8 grams Fe / 1 mole Fe = 1.43 grams Fe
(The moles cancel out)
Basically you're just multiplying the molar mass of Fe (iron) by the moles of 2.56 • 10^-3 Fe (iron), to find how many grams are in it.
2.56 • 10^-3 moles Fe = 1.43 grams Fe
