Question

If the conversion of 77.0% pure ferric oxide to iron and oxygen is 85.0% efficient, what mass of this ferric oxide is required to make 4.00 moles of iron?

Answer 1

molar mass of of Fe₂O₃ = 159.69 g/mole

Balancing equation 4 Fe + 3 O₂   2 Fe₂O₃

to produce 4 moles of Iron we require 2 moles of Fe₂O₃

2 Fe₂O₃ = 2159.69

= 319.38

above value is taken as X.

Now we have to calculate the mass of the ferric oxide required to make 4 moles of Iron is 77% of 85% X

= 0.77 0.85 319.38

= 209.03421