Question

How many grams of CO are needed with an excess of Fe2O3 to produce 35.0 g Fe?

Answer 1

Carbon ii oxide (CO) acts as a reducing agent such that it reduces oxides of less reactive metals in the reactivity series such as lead, copper and zinc.
Therefore a reaction between carbon ii oxide and iron ii oxide will be;
Fe2O3 (s) + 3CO (g) = 3CO2 (g) + 2Fe (s)
 The mass of 35 g of Fe contains  0.625 moles  ( 35 g ÷56 g)
Using the mole ratio of CO : Fe which is 3:2 , we can get the number of mole of CO needed,
 That is 0.625 × 3/ 2 = 0.9375 moles
Therefore, 0.9375 moles are required, but 1 mole of CO = 28 g,
the mass of CO required will therefore be 0.9375 × 28 = 26.25 g
thus 26.25 g of CO are needed