Example Question #6 : Stoichiometry
When the equation for the reaction shown below is balanced with the lowest whole-number coefficients, what is the sum of the coefficients of the reactants?
___ ___ ___ ___
The coefficients of the equation, when balanced, should be 2, 13, 10, and 8. This problem wants to know the sum of the reactants, so only the coefficients on the left side of the reactants should be added. The sum of 2 and 13 is 15, so 15 is the correct answer.