The mass of 0.7891 mol of ferric oxide (Fe2O3) is 125.94 grams
calculation
mass of Fe2O3 is calculated using moles Fe2O3/ molar mass of Fe2O3 formula
moles of Fe2O3 = 0.7891 moles
molar mass of Fe2O3= (55.8 x2) + (16 x3) =159.6 g/mol
mass is therefore =0.7891 mol x 159.6 g/mol=125.94 grams
