A simple way to prepare oxygen in the laboratory is by the decomposition of potassium chlorate, which occurs upon heating: 2KClO 3 ( s)→3O 2 ( g)+2KCl(s) Assuming the reaction goes to completion, if 10.0 grams of KClO 3 are decomposed according to the balanced chemical equations shown above, what mass of O 2 will be produced?