Answer:
Number of moles of Fe = 10 mol
Number of moles of CO₂ = 15 mol
Step-by-step explanation:
Given data:
Number of moles of iron oxide = 5 mol
Number of moles of carbon monoxide = 25 mol
Number of moles of product = ?
Solution:
Fe₂O₃ + 3CO → 2Fe + 3CO₂
Now we will compare the moles of reactant with product.
 Fe₂O₃ : Fe
 1 : 2
 5 : 2×5 = 10 mol
  Fe₂O₃ : CO₂
 1 : 3
 5 : 3×5 = 15 mol 
 CO : Fe
 3 : 2
 25 : 2/3×25 = 16.7 mol
  CO : CO₂
 3 : 3
 25 : 25 
Less number of moles of Fe and CO₂ are formed by iron oxide thus it will act as limiting reactant while CO is inn excess.