Molar ratio is the proportion of one substance to another in a
given chemical reaction. It is the ratio of their coefficients in
the chemical equation.
For example, in the synthesis of water, the mole ratio of Hydrogen (H2) to Oxygen (O2) is 1:2...
H2 (g) + 2O2 (g) ----> 2H2O (l)
I don't really know the answer but i know that the meaning is the ratio of mole one reactant product to the moles of another reactant.
tells you the relative amounts of reactants and products