Fe2O3 (s) + 3 CO (g) 🡪 2 Fe (s) + 3 CO2 (g)

Question

Calculate the number of grams of CO that can react with 250 g of Fe2O3.

Calculate the number of grams of Fe and the number of grams of CO2 formed when 250 grams of Fe2O3 reacts.

Answer 1

The first step is checking to see that the reaction is balanced.

Fe2O3 (s) + 3 CO (g) 🡪 2 Fe (s) + 3 CO2 (g)

In the first half of the reaction there are the following number of each element:

2 Fe 6 O 3 C

In the second half of the reaction there are the following number of each element:

2 Fe 6 O 3 C

Therefore we know the reaction is balanced. This means there is an accurate molar ratio. For every mole of Fe₂O₃ there are 3 moles of CO, 2 moles of Fe, and 3 moles of CO₂

The next step is to calculate the number of moles of Fe₂O₃ are in 250 grams. First calculate the molar mass.

Look up the molecular weight on the period table of the 3 elements in the equation.

Fe = 55.845 O = 15.999 C = 12.011

Calculate the molecular weight of the three molecules in the equation.

Fe₂O₃ = 2(55.845) + 3(15.999) = 111.69 + 47.997 = 159.687 g/mol

CO = 12.011 + 15.999 = 28.01 g/mol

CO₂ = 12.011 + 2(15.999) = 44.009 g/mol

Use the molecular mass of Fe₂O₃ to convert 250 g to moles.

250 g Fe₂O₃ x 1 mole Fe₂O₃ = 1.566 moles Fe₂O₃

159.687 g Fe₂O₃

To figure out the number of moles of Fe and CO₂ formed use the ratios from the balanced reaction. We figured out that for every mole of Fe₂O₃ there are 2 moles of Fe and 3 moles of CO₂

1.566 x 2 = 3.132 moles Fe

1.566 x 3 = 4.698 moles CO₂

To get the final answer of how many grams of each molecule are formed use the molar mass to convert to grams.

3.132 moles Fe x 55.845 g = 174.91 g Fe

1 mol

4.698 moles CO₂ x 44.009 g = 206.75 g CO₂

1 mol