2KMnO4 \(\rightarrow\)K2MnO4 + MnO2 + O2
mKMnO4 nguyên chất=69,52.\(\dfrac{90}{100}=62,568\left(g\right)\)
nKMnO4=\(\dfrac{62,568}{158}=0,396\left(mol\right)\)
Theo PTHH ta có:
\(\dfrac{1}{2}\)nKMnO4=nO2=0,198(mol)
VO2=22,4.0,198=4,4352(lít)
Vì chứa 10% tạp chất
=> mKMnO4 chỉ chiếm 90%
=> mKMnO4 = 69,52 . 90% = 62,568
=> nKMnO4 = \(\dfrac{62,568}{158}\) = 0,396 ( mol )
2KMnO4 \(\rightarrow\) K2MnO4 + MnO2 + O2
0,396..........................................0,198
=> VO2 = 22,4 . 0,198 = 4,4352 ( lít )