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![](https://rs.olm.vn/images/avt/0.png?1311)
a, PT: \(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)
b, Ta có: \(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)
Theo PT: \(n_{O_2}=\dfrac{3}{4}n_{Al}=0,15\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,15.22,4=3,36\left(l\right)\)
c, Theo PT: \(n_{Al_2O_3}=\dfrac{1}{2}n_{Al}=0,1\left(mol\right)\)
\(\Rightarrow m_{Al_2O_3}=0,1.102=10,2\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a: \(4Al+3O_2\rightarrow2Al_2O_3\)
c: \(n_{Al}=\dfrac{2.4}{24}=0.1\left(mol\right)\)
\(\Leftrightarrow n_{Al_2O_3}=0.05\left(mol\right)\)
\(m_{Al_2O_3}=0.05\cdot96=1.92\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
nAl=16,2/27= 0,6(mol)
a) PTHH: 4 Al +3 O2 -to-> 2 Al2O3
nO2= 3/4 . nAl=3/4 . 0,6= 0,45(mol)
=> V(O2,đktc)=0,45 x 22,4=10,08(l)
b) nAl2O3= nAl/2=0,6/2=0,3(mol)
=>mAl2O3=102. 0,3= 30,6(g)
c) 2KMnO4 -to-> K2MnO4 + MnO2 + O2
nKMnO4= 2.nO2=2. 0,45=0,9(mol)
=>mKMnO4= 158 x 0,9= 142,2(g)
![](https://rs.olm.vn/images/avt/0.png?1311)
a, \(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)
b, \(n_{Al_2O_3}=\dfrac{20,4}{102}=0,2\left(mol\right)\)
Theo PT: \(n_{O_2}=\dfrac{3}{2}n_{Al_2O_3}=0,3\left(mol\right)\Rightarrow V_{O_2}=0,3.22,4=6,72\left(l\right)\)
c, \(V_{kk}=\dfrac{V_{O_2}}{20\%}=33,6\left(l\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_{Al}=\dfrac{3,24}{27}=0,12mol\)
a)\(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\) \(\Rightarrow\) phản ứng hóa hợp.
b)0,12 0,09 0,06
\(m_{Al_2O_3}=0,06\cdot102=6,12g\)
c)\(V_{O_2}=0,09\cdot22,4=2,016l\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a, PT: \(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)
Ta có: \(n_{Al}=\dfrac{10,2}{27}=\dfrac{17}{45}\left(mol\right)\)
b, Theo PT: \(n_{O_2}=\dfrac{3}{4}n_{Al}=\dfrac{17}{60}\left(mol\right)\)
\(\Rightarrow V_{O_2}=\dfrac{17}{60}.22,4\approx6,347\left(l\right)\)
c, Theo PT: \(n_{Al_2O_3}=\dfrac{1}{2}n_{Al}=\dfrac{17}{90}\left(mol\right)\)
\(\Rightarrow m_{Al_2O_3}=\dfrac{17}{90}.102\approx19,267\left(g\right)\)
d, PT: \(2KMnO_4\underrightarrow{t^o}K_2MnO_4+MnO_2+O_2\)
Theo PT: \(n_{KMnO_4}=2n_{O_2}=\dfrac{17}{30}\left(mol\right)\)
\(\Rightarrow m_{KMnO_3}=\dfrac{17}{30}.158\approx89,53\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(a,\) Nhôm + Oxi \(\xrightarrow{t^o}\) Nhôm Oxit
\(b,4Al+3O_2\xrightarrow{t^o}2Al_2O_3\\ c,\text{Bảo toàn KL: }m_{O_2}=m_{Al_2O_3}-m_{Al}=40,8-21,6=19,2(g)\)
\(a.Nhôm+Oxi\rightarrow NhômOxit\\ b.4Al+3O_2-^{t^o}\rightarrow2Al_2O_3\\ c.BTKL\Rightarrow m_{O_2}=m_{Al_2O_3}-m_{Al}=40,8-21,6=19,2\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
nAl = 2,7/27 = 0,1 (mol)
PTHH: 4Al + 3O2 -> (t°) 2Al2O3
Mol: 0,1 ---> 0,075 ---> 0,05
mAl2O3 = 0,05 . 102 = 5,1 (g)
VO2 = 0,075 . 22,4 = 1,68 (l)
Vkk = 1,68 . 5 = 8,4 (l)
\(n_{Al}=\dfrac{m_{Al}}{M_{Al}}=\dfrac{2,7}{27}=0,1mol\)
\(4Al+3O_2\rightarrow\left(t^o\right)2Al_2O_3\)
0,1 0,075 0,05 ( mol )
\(m_{Al_2O_3}=n_{Al_2O_3}.M_{Al_2O_3}=0,05.102=5,1g\)
\(V_{kk}=V_{O_2}.5=\left(0,075.22,4\right).5=8,4l\)
a/ PTHH
\(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)
b/
Ta có: \(n_{Al_2O_3}=\dfrac{10.2}{102}=0.1\left(mol\right)\)
\(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)
4 2
x 0.1
\(=>x=\dfrac{0.1\cdot4}{2}=0.2=n_{Al}\)
\(=>m_{Al}=0.2\cdot27=5.4\left(g\right)\)