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

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