Why must an equation be balanced?

Balanced coefficients represent conserved atoms and supply the correct mole ratios.

What if both reactants are present in excess?

One must still be limiting for a finite batch; equal reaction-equivalent amounts indicate both are consumed together.

Balance first, convert grams to moles, compare mole ratios, and calculate the theoretical yield.

The limiting reactant is the reactant that can make the least product after dividing its available moles by its balanced-equation coefficient.

n = m/M; product n = limiting n × coefficient ratio

Enter your values in the browser tool to see the result, worked steps, assumptions, and related learning guides.