Twenty dietary iron tablets with a total mass of 22.131 g were ground and mixed thoroughly. Then 2.998 g of the powder was dissolved in concentrated HNO3 and heated to convert all the iron to Fe3+. Addition of NH3 caused quantitative precipitation of Fe2O3 (FW 159.69). What is the average mass of FeSO47H2O (FM 278.01) in each tablet?