Answer:
The percentage yield of O2 is 66.7%
Explanation:
Reaction for decomposition of potassium chlorate is:
2KClO₃ → 2KCl + 3O₂
The products are potassium chloride and oxygen.
Let's find out the moles of chlorate.
Mass / Molar mass = Moles
12.3 g / 123 g/mol = 0.1 mol
So ratio is 2:3, 2 moles of chlorate produce 3 mol of oxygen.
Then, 0.1 mol of chlorate may produce (0.1 .3)/ 2 = 0.15 moles
Let's convert the moles of produced oxygen, as to find out the theoretical yield.
0.15 mol . 32 g/ 1mol = 4.8 g
To calculate the percentage yield, the formula is
(Produced Yield / Theoretical yield) . 100 =
(3.2g / 4.8g) . 100 = 66.7 %
of 
, and 
of 