Answer:
5.81×10²² molecules of oxygen.
Step-by-step explanation:
This a reaction of decomposition:
2KClO₃ → 2KCl + 3O₂
2 moles of potassium chlorate can produce 2 moles of potassium chloride and 3 moles of oxygen.
We determine the amount of salt.
7.89 g. 1mol /122.55g = 0.0644 moles.
If 2 moles of salt, can produce 3 moles of oxygen.
0.0644 moles of salt may produce (0.0644 . 3) /2 = 0.0966 moles.
Let's count the molecules.
1 mol oxygen contains 6.02×10²³ molecules
Then, 0.0966 moles may contain (0.0966 . NA) = 5.81×10²² molecules