On heating 12.25g of KClO3 for 2 minutes, there is a weight loss of 0.96 g.
2KClO3(s) => 2KCl(s) + 3O2(g)
What percentage by mass of the original KClO3 has decomposed?
F.4 Chemistry
2007-12-12 11:37 pm
回答 (1)
2007-12-12 11:46 pm
✔ 最佳答案
2KClO3 → 2KCl + 3O2 The weight loss is due to the evolve of oxygen
No. of mole of oxygen
= Mass / molar mass
= 0.96 / (16.0 X 2)
= 0.03 mol
According to the equation above, mole ratio of KClO3 : O2 = 2 : 3
So, no. of mol of KClO3 reacted
= 2 / 3 X 0.03
= 0.02 mol
Molar mass of KClO3
= 39.1 + 35.5 + 16.0 X 3
= 122.6 gmol-1
So, mass of KClO3 reacted
= no. of mole X molar mass
= 0.02 X 122.6
= 2.452 g
Therefore, percentage of mass reacted
= 2.452 / 12.25 X 100%
= 20.0%
參考: Myself~~~
收錄日期: 2021-04-20 13:33:53
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