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a, \(PTHH:3Fe+2O_2\rightarrow Fe_3O_4\)
Theo PTHH : \(n_{Fe}=3n_{Fe3O4}=3.\dfrac{m}{M}=0,45\left(mol\right)\)
\(\Rightarrow m_{Fe}=25,2g\)
b, Theo PTHH : \(n_{O2}=n_{Fe3O4}=0,3\left(mol\right)\)
\(\Rightarrow V_{O2}=6,72\left(l\right)\)
c, PTHH : \(2KClO_3\rightarrow2KCl+3O_2\)
Theo PTHH : \(n_{KClO3}=\dfrac{2}{3}n_{O2}=0,25\left(mol\right)\)
\(\Rightarrow m_{KClo3}=30,625g\)
PTHH: \(2KMnO_4\xrightarrow[]{t^o}K_2MnO_4+MnO_2+O_2\)
\(n_{KMnO_4}=\dfrac{m_{KMnO_4}}{M_{KMnO_4}}=\dfrac{15,8}{158}=0,1\left(mol\right)\)
a. Theo PTHH: \(n_{O_2}=\dfrac{1}{2}n_{KMnO_4}=\dfrac{1}{2}0,1=0,05\left(mol\right)\)
\(\Rightarrow V_{O_2}=n_{O_2}.22,4=0,05.22,4=1,12\left(l\right)\)
b. PTHH: \(3Fe+2O_2\xrightarrow[]{t^o}Fe_3O_4\)
\(n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\)
Ta có: \(\dfrac{1}{n_{O_2}}=\dfrac{1}{0,05}\)
\(\dfrac{1}{n_{Fe}}=\dfrac{1}{0,1}\)
\(\Rightarrow\dfrac{1}{n_{O_2}}>\dfrac{1}{n_{Fe}}\)
Vậy Fe dư
Theo PTHH: \(n_{Fe_3O_4}=\dfrac{0,1.1}{3}=\dfrac{1}{30}\left(mol\right)\)
\(\Rightarrow m_{Fe_3O_4}=n_{Fe_3O_4}.M_{Fe_3O_4}=\dfrac{1}{30}.232\approx7,73g\)
a)
\(b)n_{Fe_3O_4} = \dfrac{6,96}{232} = 0,03(mol)\\ 3Fe + 2O_2 \xrightarrow{t^o}Fe_3O_4\\ n_{Fe} = 3n_{Fe_3O_4} = 0,09(mol)\\ m_{Fe} = 0,09.56 = 5,04(gam)\\ c) n_{O_2} = 2n_{Fe_3O_4} = 0,06(mol)\\ V_{O_2} = 0,06.22,4 = 1,344(lít)\\ d) 2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2\\ n_{KMnO_4} = 2n_{O_2} = 0,12(mol)\\ m_{KMnO_4} = 0,12.158 = 18,96(gam)\)
\(n_{Fe_3O_4}=\dfrac{6.96}{232}=0.03\left(mol\right)\)
\(3Fe+2O_2\underrightarrow{t^0}Fe_2O_3\)
\(0.09.....0.06.......0.03\)
\(m_{Fe}=0.09\cdot56=5.04\left(g\right)\)
\(V_{O_2}=0.06\cdot22.4=1.344\left(l\right)\)
\(2KMnO_4\underrightarrow{t^0}K_2MnO_4+MnO_2+O_2\)
\(0.12...............................................0.06\)
\(m_{KMnO_4}=0.12\cdot158=18.96\left(g\right)\)
n Fe3O4=\(\dfrac{13,92}{232}\)=0,06 mol
3Fe + 2O2 -to--> Fe3O4
0,18------0,12-------0,06
=>m Fe=0,18.56=10,08g
=>VO2=0,12.22,4=2,688l
2KMnO4-to>K2MnO4+MnO2+O2
0,24-------------------------------------0,12
=>m KMnO4=0,24.158=37,92g
nFe3O4 = 13,92 : 160= 0,087 (mol)
pthh : 3Fe + 2O2 -t--> Fe3O4
0,087->0,058-->0,029 (mol)
=> mFe = 0,029 . 56 = 1,624 (g)
=> VO2 = 0,058 . 22,4 = 1,2992 (L)
pthh : 2KMnO4 -t--> K2MnO4 + MnO2 + O2
0,116<------------------------------0,058 (mol)
=> mKMnO4 = 0,116 . 158 = 18,328 (g)
\(n_{Fe_3O_4}=\dfrac{m_{Fe_3O_4}}{M_{Fe_3O_4}}=\dfrac{23,2}{232}=0,1mol\)
\(3Fe+2O_2\rightarrow\left(t^o\right)Fe_3O_4\)
0,3 0,2 0,1 ( mol )
\(m_{Fe}=n_{Fe}.M_{Fe}=0,3.56=16,8g\)
\(V_{O_2}=n_{O_2}.22,4=0,2.22,4=4,48l\)
\(V_{kk}=\dfrac{4,48.100}{20}=22,4l\)
\(2KMnO_4\rightarrow\left(t^o\right)K_2MnO_4+MnO_2+O_2\)
0,4 0,2 ( mol )
\(n_{KMnO_4}=\dfrac{0,4}{85\%}=\dfrac{8}{17}mol\)
\(m_{KMnO_4}=n_{KMnO_4}.M_{KMnO_4}=\dfrac{8}{17}.158=74,3529g\)
a)\(n_{Fe}=\dfrac{22,4}{56}=0,4mol\)
\(3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\)
0,4 \(\dfrac{4}{15}\) \(\dfrac{2}{15}\)
\(V_{O_2}=\dfrac{4}{15}\cdot22,4=5,973l\)
b)\(2KClO_3\underrightarrow{t^o}2KCl+3O_2\)
\(\dfrac{8}{45}\) \(\dfrac{4}{15}\)
\(m_{KClO_3}=\dfrac{8}{45}\cdot122,5=21,78g\)
PT: \(3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\)
a, Ta có: \(n_{Fe}=\dfrac{8,4}{56}=0,15\left(mol\right)\)
Theo PT: \(n_{O_2}=\dfrac{2}{3}n_{Fe}=0,1\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,1.22,4=2,24\left(l\right)\)
b, Theo PT: \(n_{Fe_3O_4}=\dfrac{1}{2}n_{O_2}=0,075\left(mol\right)\)
\(\Rightarrow m_{Fe_3O_4}=0,075.232=17,4\left(g\right)\)
c, PT: \(2KMnO_4\underrightarrow{t^o}KMnO_4+MnO_2+O_2\)
Theo PT: \(n_{KMnO_4}=2n_{O_2}=0,2\left(mol\right)\)
\(\Rightarrow m_{KMnO_4}=0,2.158=31,6\left(g\right)\)
Bạn tham khảo nhé!
Cảm ơn bạn @anayuiky đã nhắc lỗi sai. Mình sửa lại ý c):
PTHH: \(2KMnO_4\rightarrow^{t^o}K_2MnO_4+MnO_2+O_2\uparrow\)
Theo phương trình \(n_{KMnO_4}=n_{O_2}.2=0,25.2=0,5mol\)
\(\rightarrow m_{KMnO_4}=0,5.\left(39+55+16.4\right)=79g\)
a. \(n_{H_2}=\frac{V}{22,4}=\frac{11,2}{22,4}=0,5mol\)
\(n_{O_2}=\frac{V}{22,4}=\frac{10,08}{22,4}=0,45mol\)
PTHH: \(2H_2+O_2\rightarrow^{t^o}2H_2O\)
Ban đầu: 0,5 0,45 mol
Trong pứng: 0,5 0,25 0,5 mol
Sau pứng: 0 0,2 0,5 mol
\(\rightarrow M_{O_2\left(dư\right)}=n.M=0,2.32=6,4g\)
b. Theo phương trình \(n_{H_2O}=n_{H_2}=0,5mol\)
\(\rightarrow m_{H_2O}=n.M=0,5.18=9g\)
c. PTHH: \(2KMnO_4\rightarrow^{t^o}K_2MnO_4+MnO_2+O_2\uparrow\)
0,9 0,45 mol
\(\rightarrow n_{KMnO_4}=\frac{2}{1}n_{O_2}=\frac{0,45.2}{1}=0,9mol\)
\(\rightarrow m_{KMnO_4}=n.M=0,9.158=142,2g\)
\(a) n_{O_2} = \dfrac{2,24}{22,4} = 0,1(mol)\\ 3Fe + 2O_2 \xrightarrow{t^o} Fe_3O_4\\ n_{Fe} = \dfrac{3}{2}n_{O_2} = 0,15(mol)\\ m_{Fe} = 0,15.56 = 8,4(gam)\\ b) \%Fe = \dfrac{56.3}{56.3+16.4}.100\% = 72,41\% \%O = 100\% - 72,41\% = 27,59\%\\ c) 2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2\\ n_{KMnO_4} = 2n_{O_2} = 0,2(mol)\\ m_{KMnO_4} = 0,2.158 = 31,6(gam)\)
\(n_{O_2}=\dfrac{2.24}{22.4}=0.1\left(mol\right)\)
\(3Fe+2O_2\underrightarrow{t^0}Fe_3O_4\)
\(0.15.......0.1......0.05\)
\(m_{Fe_3O_4}=0.05\cdot232=11.6\left(g\right)\)
\(\%Fe=\dfrac{0.05\cdot3\cdot56}{11.6}\cdot100\%=72.41\%\)
\(\%O=10072.41=27.59\%\)
\(2KMnO_4\underrightarrow{t^0}K_2MnO_4+MnO_2+O_2\)
\(0.2...................................................0.1\)
\(m_{_{ }KMnO_4}=0.2\cdot158=31.6\left(g\right)\)