Mole Ratio
The proportion between the amounts of any two substances in a reaction, taken directly from the balanced equation's coefficients.
Formula / equation
n_A : n_B = a : b
Unit
Dimensionless
In depth
The mole ratio is the bridge that carries a calculation from one substance to another, and it is the only step in stoichiometry that requires the equation itself. Used as a conversion factor with the required substance on top, it makes the unwanted unit cancel cleanly.
Examples in the real world
In 2H₂ + O₂ → 2H₂O the H₂:O₂ ratio is 2:1, so 0.50 mol of oxygen consumes 1.0 mol of hydrogen.