How many grams of O2 are produced in the decomposition of 40.6 g KClO3?

Answer 1

I believe the rxn is KClO3 => KOCl + O2.
So if you divide 40.6 by the mol wt of KClO3 you will get the moles of that compound and also of the O2 dimer. To find the grams of O2, multiply the number of moles by 32.