If each tablet of a dietary supplement contains ~20 mg of iron how many tablets should we analyze to provide ~.50g of Fe2O3?

Answer 1

0.50 g Fe2O3 x (2*molar mass Fe/molar mass Fe2O3) = ?? g Fe = about 0.35 g = about 350 mg. 1 tab = about 20 mg.
20 mg/tab x #tab = 350 mg.
Solve for # tab. You need to go through it for better accuracy.