A major reason we balance equations is to find the ratio between substances in the equation. The coefficients represent the ratios of substances. We often think of the coefficients as moles. The ratio is called the Mole Ratio.
The mole ratio is the key to equation stoichiometry.
In stoichiometry, we only use the coefficients in the Mole Ratio. We can think of the coefficients as moles!
One way to find the the mole ratio is:
We get the coefficients from the balanced equation.