Question

giai de hoa hoc trong phong thi nghiem oxi duoc dieu che bang cach nhiet KCLO3 hoac KMNO4 Tinh khoi luong KCLO3 Hoac KMNO4 Can dung de dieu che duoc 0.72 lit khi oxi o DKTC (cho O=16, Cl = 35,5 , K = 39 , Mn = 55)

Answer 1

\(n_{O_2} = \dfrac{0,72}{22,4} = \dfrac{9}{280}(mol)\\ 2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2\\ n_{KMnO_4} = 2n_{O_2} = \dfrac{9}{140}(mol)\\ m_{KMnO_4} = \dfrac{9}{140}.158 = 10,16(gam)\\ 2KClO_3 \xrightarrow{t^o} 2KCl + 3O_2\\ n_{KClO_3} = \dfrac{2}{3}n_{O_2} = \dfrac{3}{140}(mol)\\ m_{KClO_3} = \dfrac{3}{140}.122,5 = 2,625(gam)\)

Answer 2

\(n_{O_2}=\dfrac{6.72}{22.4}=0.3\left(mol\right)\)

\(2KMnO_4\underrightarrow{t^0}K_2MnO_4+MnO_2+O_2\)

\(0.6..............................................0.3\)

\(2KClO_3\underrightarrow{t^0}2KCl+3O_2\)

\(0.2..........................0.3\)

\(m_{KMnO_4}=0.6\cdot158=94.8\left(g\right)\)

\(m_{KClO_3}=0.2\cdot122.5=24.5\left(g\right)\)

Answer 3

\(n_{O_2}=\dfrac{V_{O_2\left(ĐKTC\right)}}{22,4}=\dfrac{0,72}{22,4}=0,03\left(mol\right)\)

- Điều chế O2 bằng KMnO4, ta có PTHH: 

\(2KMnO_4\underrightarrow{t^o}K_2MnO_4+MnO_2+O_2\)

----2----------------------------------------------------1---

----0,06------------------------------------------------0,03---

\(m_{KMnO_4}=n_{KMnO_4}\cdot M_{KMnO_4}=0,06\cdot158=9,48\left(g\right)\)

- Điều chế O2 bằng KClO3, ta có PTHH:

\(2KClO_3\xrightarrow[MnO_2]{t^o}2KCl+3O_2\)

---2-------------------------------------3----

---0,02---------------------------------0,03----

\(m_{KClO_3}=n_{KClO_3}\cdot M_{KClO_3}=0,02\cdot122,5=2,45\left(g\right)\)

 

Answer 4

nO2=\(\dfrac{0,72}{32}\)=0,0225(mol)

PTHH 1 2KMnO4 →K2MnO4 +MnO2 +O2

Theo PTHH 1 ta có nKMnO4= 2 * 0,0225 = 0,045 (mol)

mKMnO4= 0,045 * 158= 7,11(g)

PTHH 2 : 2KClO3 → 2KCl + 3O2

Theo PTHH 2 ta có: nKClO3= \(\dfrac{2}{3}\) 0,0225 =0,015(mol)

m KClO3= 0,015 * 122,5 = 1,8375 (g)

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