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a) \(n_{O_2}=\dfrac{11,2.20\%}{22,4}=0,1\left(mol\right)\)
PTHH: 2Mg + O2 --to--> 2MgO
0,2<--0,1--------->0,2
=> mMg = 0,2.24 = 4,8 (g)
b) nMgO = 0,2.40 = 8 (g)
\(n_{O_2}=\dfrac{V}{22,4}=\dfrac{11,2}{22,4}=0,5mol\)
PTHH:
\(2Mg+O_2->2MgO\)
2 : 1 : 2 mol
1 : 0,5 : 1 mol
\(m_{Mg}=n.M=1.24=24g\)
\(m_{MgO}=n.M=1.\left(24+16\right)=40g\)
nO2 = 11,2/22,4 = 0,5 (mol)
PTHH: 2Mg + O2 -> (t°) 2MgO
Mol: 1 <--- 0,5 ---> 1
mMg = 1 . 24 = 24 (g)
mMgO = 1 . 40 = 40 (g)
a)\(2Mg + O_2 \xrightarrow{t^o} 2MgO\)
b)
\(n_{Mg} = \dfrac{2,4}{24} = 0,1(mol)\)
Theo PTHH :
\(n_{O_2} = \dfrac{1}{2}n_{Mg} = 0,05(mol)\\ \Rightarrow V_{O_2} = 0,05.22,4 = 1,12(lít)\)
c)
\(n_{MgO} = n_{Mg} = 0,1(mol)\\ \Rightarrow m_{MgO} = 0,1.40 = 4(gam)\)
d)
\(V_{không\ khí} = 5V_{O_2} = 1,12.5 = 5,6(lít)\)
\(n_{Mg}=\dfrac{2,4}{24}=0,1\left(mol\right)\\ a,2Mg+O_2\rightarrow\left(t^o\right)2MgO\\ n_{O_2}=\dfrac{0,1}{2}=0,05\left(mol\right)\\ V_{O_2\left(đktc\right)}=0,05.22,4=1,12\left(l\right)\\ b,2KClO_3\rightarrow\left(t^o\right)2KCl+3O_2\\ n_{KClO_3}=\dfrac{0,05.2}{3}=\dfrac{1}{30}\left(mol\right)\\ \Rightarrow m_{KClO_3}=\dfrac{122,5}{30}=\dfrac{49}{12}\left(g\right)\)
1. a. \(PTHH:2Mg+O_2\overset{t^o}{--->}2MgO\left(1\right)\)
b. Ta có: \(n_{Mg}=\dfrac{24}{24}=1\left(mol\right)\)
Theo PT(1): \(n_{O_2}=\dfrac{1}{2}.n_{Mg}=\dfrac{1}{2}.0,1=0,5\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,5.22,4=11,2\left(lít\right)\)
c. \(PTHH:2KClO_3\xrightarrow[t^o]{MnO_2}2KCl+3O_2\left(2\right)\)
Theo PT(2): \(n_{KClO_3}=\dfrac{2}{3}.n_{O_2}=\dfrac{2}{3}.0,5=\dfrac{1}{3}\left(mol\right)\)
\(\Rightarrow m_{KClO_3}=\dfrac{1}{3}.122,5=40,83\left(g\right)\)
2. \(PTHH:3Fe+2O_2\overset{t^o}{--->}Fe_3O_4\)
Ta có: \(n_{Fe_3O_4}=\dfrac{2,32}{232}=0,01\left(mol\right)\)
a. Theo PT: \(n_{Fe}=3.n_{Fe_3O_4}=0,01.3=0,03\left(mol\right)\)
\(\Rightarrow m_{Fe}=0,03.56=1,68\left(g\right)\)
b. Theo PT: \(n_{O_2}=2.n_{Fe_3O_4}=2.0,01=0,02\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,02.22,4=0,448\left(lít\right)\)
\(n_{Cu}=\dfrac{32}{64}=0,5mol\)
\(2Cu+O_2\rightarrow\left(t^o\right)2CuO\)
0,5 0,25 0,5 ( mol )
\(m_{CuO}=0,5.80=40g\)
\(V_{O_2}=0,25.22,4=5,6l\)
a) \(n_{Cu}=\dfrac{32}{64}=0,5\left(mol\right)\)
PTHH: 2Cu + O2 --to--> 2CuO
0,5-->0,25------>0,5
=> mCuO = 0,5.80 = 40 (g)
b) VO2 = 0,25.22,4 = 5,6 (l)
nMg = 9,6/24 = 0,4 (mol)
2Mg + O2 ---to---> 2MgO
0,4____0,2_________0,4
VO2(đktc) = 0,2.22,4 = 4,48(l)
mMgO = 0,4.40 = 16(g)
a, \(2Mg+O_2\underrightarrow{^{t^o}}2MgO\)
\(n_{MgO}=\dfrac{2}{40}=0,05\left(mol\right)\)
\(n_{O_2}=\dfrac{1}{2}n_{MgO}=0,025\left(mol\right)\Rightarrow V_{O_2}=0,025.22,4=0,56\left(l\right)\)
b, Có lẽ đề cho oxi tác dụng với hidro chứ không phải oxit bạn nhỉ?
\(n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
PT: \(2H_2+O_2\underrightarrow{^{t^o}}2H_2O\)
Xét tỉ lệ: \(\dfrac{0,15}{2}>\dfrac{0,025}{1}\), ta được H2 dư.
THeo PT: \(n_{H_2O}=2n_{O_2}=0,05\left(mol\right)\Rightarrow m_{H_2O}=0,05.18=0,9\left(g\right)\)
\(n_{Mg}=\dfrac{4.8}{24}=0.2\left(mol\right)\)
\(2Mg+O_2\underrightarrow{t^0}2MgO\)
\(0.2.......0.1........0.2\)
\(V_{O_2}=0.1\cdot22.4=2.24\left(l\right)\)
\(m_{MgO}=0.2\cdot40=8\left(g\right)\)
a)
2Mg + O2 --to--> 2MgO
0,2----->0,1------>0,2 (mol)
nMg = 4,48/24 = 0,2 (mol)
=> VO2 = 0,1.22,4 = 2,24 (lít)
b) mMgO = 0,2.(24 + 16) = 8 (g)