An example of a limiting reactant stoichiometry problem:

How many grams of H₂O are produced in the reaction:

CH₄ + 2O₂  --> CO₂ + 2H₂O

if 50.0 g of CH₄ reacts with and excess of 100 g of O₂?

This must then be solved twice, first using CH₄ and the using O₂.

For the CH₄ it's the same as before (that's because I'm lazy so I picked the same number of grams of CH₄):



Compare this to:

Answer number 2 is therefore the correct answer since it is the lower answer.