How many kilograms of red iron oxide can be obtained from 1.00kg ferrous sulfate heptahydrate?
I'll let you in on a little secret; we are not REQUIRED (although it looks better) to convert kg to grams.
So how many kgmoles are in 1.00 kg FeSO4.7H2O
1.00 kg/molar mass FeSO4.7H2O (in kg) = 1.00/276 = zz kg moles
Then zz moles FeSO4.7H2O x (1 mole Fe/1 mole FeSO4.7H2O) x (1 mole Fe2O3/2 moles Fe) = zz moles FeSO4.7H2O x 1/1 x 1/2 = zz/2 moles = yy moles Fe2O3
grams = moles x molar mass Fe2O3 and the answer will be in kg. You should confirm the molar masses I've used.