What information in a balanced chemical equation shows how many miles of a reactant are involved in the reaction?

A balanced chemical equation does not provide information on the physical amount or quantity of reactants involved in a reaction, such as miles. The coefficients in a balanced chemical equation represent the mole ratio of reactants and products, not physical quantities like miles. To determine how many moles or amount of reactant is involved in a reaction, one would need to use stoichiometry calculations based on the coefficients in the balanced equation and known quantities.