Mole ratio is the ratio of the number of moles of two compounds in a balanced chemical reaction. Number of moles of a compound in a chemical reaction is the number written before the compound.
For example, the mole ratio of Iron (Fe) and water (H₂O) in the equation below is 3:4
3Fe + 4H₂O ⇒ Fe₃O₄ + 4H₂
Thus, mole ratio does not compare subscripts of compounds.
