moles=mass of substance
0.500=mass/2[55.8]+3[16]
0.500=mass/111.6+48
0.500 x 159.6=mass
mass=79.8g
In order to calculate the number of grams in .5 moles of fe2o3, you have to use the above calculations. .5mol= x/2(55.8) + 3(16). then, you can solve the equation for the answer which is 79.8 grams.
