Question

Iron and oxygen gas react in a combination reaction to form iron(III) oxide. How many moles of iron are needed to make 5.0 moles of iron(III) oxide? Hint: Write and balance the chemical equation.

Multiple Choice

• 2.5 mol

• 10. mol

• 5.0 mol

• 1.0 mol

• 0.50 mol

Answer 1

Ans.

The balanced combination reaction of iron and oxygen gas is as shown below:

According to the balanced chemical reaction, 4 moles of iron will react with 2 moles of oxygen gas to form 2 moles of Fe₂O₃

In other words, to make 2 moles of Fe₂O₃, 4 moles of Fe is required.

Therefore, 1 mole of Fe₂O₃ will require no. of mole of Fe given by

And, 5 mole of Fe₂O₃ will require no. of mol of Fe given by

Therefore, 10 moles of Fe is required to make 5 moles of Fe₂O₃.