According to the balanced equation: 2KCIO3 → 2KCI + 3O2, it shows that for every 2 moles of KCIO3 decomposed, 3 moles of O2 are formed.
Given that 1.0 mole of KCIO3 decomposes, we can use the mole ratio from the balanced equation to determine the number of moles of O2 formed.
1.0 mole KCIO3 × (3 moles O2 / 2 moles KCIO3) = 1.5 moles O2
Therefore, 1.5 moles of O2 are formed when 1.0 mole of KCIO3 decomposes.