When heated, KClO3 decomposes into KCl and O2. If this reaction produced 79.9 g of KCl, how much O2 was produced (in grams)?

Answer 1

2 KClO3 ---> 2 KCl + 3 O2

moles O2 = 3/2 * moles KCl

moles KCl = mass KCl / molar mass KCl

mass O2 = moles O2 * molar mass O2