\(n_{Fe_3O_4}=\dfrac{23,2}{232}=0,1mol\)

\(3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\)

0,3      0,2       0,1

\(V_{O_2}=0,2\cdot22,4=4,48l\)

\(n_{Fe_3O_4}=\dfrac{23,2}{232}=0,1mol\)

\(3Fe+2O_2\rightarrow\left(t^o\right)Fe_3O_4\)

           0,2                 0,1    ( mol )

\(V_{O_2}=0,2.22,4=4,48l\)

a, \(Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\)

b, \(n_{Fe}=\dfrac{33,6}{56}=0,6\left(mol\right)\)

Theo PT: \(n_{Fe_2O_3}=\dfrac{1}{2}n_{Fe}=0,3\left(mol\right)\Rightarrow m_{Fe_2O_3}=0,3.160=48\left(g\right)\)

c, \(n_{H_2}=\dfrac{3}{2}n_{Fe}=0,9\left(mol\right)\Rightarrow V_{H_2}=0,9.22,4=20,16\left(l\right)\)

\(n_{O_2}=\dfrac{0.896}{22.4}=0.04\left(mol\right)\)

\(3Fe+2O_2\underrightarrow{^{^{t^0}}}Fe_3O_4\)

\(0.06......0.04.......0.02\)

\(m_{Fe}=0.06\cdot56=3.36\left(g\right)\)

\(m_{Fe_2O_3}=0.02\cdot232=4.64\left(g\right)\)

3Fe+2O₂-to>Fe₃O₄

0,06----0,04-----0,02 mol

n _O2=\(\dfrac{0,896}{22,4}\)=0,04 mol

=>m _Fe=0,06.56=3,36g

=>m _Fe3O4=0,02.232=4,64g

a. -PTHH xảy ra: 3Fe+2O₂→Fe₃O₄.

-n_O2=\(\dfrac{V}{22,4}=\dfrac{0,896}{22,4}=0,04\)(mol) (bonus: ở trường mình là dùng 24,79 nhé:)

- Theo PTHH ta có:

3.n_Fe=2.n_O2=n_Fe3O4=0,04 (mol)

=>n_Fe=\(\dfrac{0,04}{3}=\dfrac{1}{75}\)(mol)

=>m_Fe=M.n=56.\(\dfrac{1}{75}\)=0,75(g).

b. n_Fe3O4=0,04 (mol)

=>m_Fe3O4=M.n=232.0,04=9,23(g)

a, \(FeO+H_2\underrightarrow{t^o}Fe+H_2O\)

b, \(n_{FeO}=\dfrac{7,2}{72}=0,1\left(mol\right)\)

\(n_{Fe}=n_{FeO}=0,1\left(mol\right)\Rightarrow m_{Fe}=0,1.56=5,6\left(g\right)\)

c, \(n_{H_2}=n_{FeO}=0,1\left(mol\right)\Rightarrow V_{H_2}=0,1.22,4=2,24\left(l\right)\)

b

B

gái :)) xinh quá

tách nhỏ nhé

8

4Al+3O2-to>2al2O3

0,2----0,15-------0,1

n O2=0,15 mol

=>m AL2o3=0,1.102=10,2g

10

4H2+Fe3O4->3Fe+4H2O

0,8-----0,2--------0,6

n Fe3O4=0,2 mol

=>m Fe=0,6.56=33,6g

=>VH2=0,8.22,4=17,92l

\(n_{Fe}=\dfrac{33.6}{56}=0.6\left(mol\right)\)

\(Fe_2O_3+3H_2\underrightarrow{^{^{t^0}}}2Fe+3H_2O\)

\(0.3..........0.9......0.6\)

\(m_{Fe_2O_3}=0.3\cdot160=48\left(g\right)\)

\(V_{H_2}=0.9\cdot22.4=20.16\left(l\right)\)

a) n Fe = 33,6/56 = 0,6(mol)

Fe2O3 + 3H2 \(\underrightarrow{t^o}\)  2Fe + 3H2O

Theo PTHH :

n Fe2O3 = 1/2 n Fe = 0,3(mol)

m Fe2O3 = 0,3.160 = 48(gam)

c) n H2 = 3/2 n Fe = 0,9(mol)

V H2 = 0,9.22,4 = 20,16(lít)

Bài 3 : 

PTHH :  \(6Fe+4O_2\left(t^o\right)->2Fe_3O_4\)      (1)

\(n_{Fe_3O_4}=\dfrac{m}{M}=\dfrac{2,32}{56.3+16.4}=0,01\left(mol\right)\)

Từ (1) => \(3n_{Fe_3O_4}=n_{Fe}=0,03\left(mol\right)\)

=> \(m_{Fe}=n.M=1,68\left(g\right)\)

Từ (1) => \(2n_{Fe_3O_4}=n_{O_2}=0,02\left(mol\right)\)

=> \(V_{O_2\left(đktc\right)}=n.22,4=0,448\left(l\right)\)

Bài 4 : 

PTHH : \(4P+5O_2\left(t^o\right)->2P_2O_5\)    (1)

\(n_P=\dfrac{m}{M}=\dfrac{6,2}{31}=0,2\left(mol\right)\)

\(n_{O_2}=\dfrac{V}{22,4}=\dfrac{6,72}{32}=0,21\left(mol\right)\)

Có : \(n_P< n_{O_2}\left(0,2< 0,21\right)\)

-> P hết ; O₂ dư

Từ (1) -> \(\dfrac{1}{2}n_P=n_{P_2O_5}=0,1\left(mol\right)\)

=> \(m_{P_2O_5}=n.M=14,2\left(g\right)\)

Bài 3:

\(n_{Fe_3O_4}=\dfrac{2,32}{232}=0,01\left(mol\right)\)

PTHH: 3Fe + 2O₂ ---t^o→ Fe₃O₄

Mol:    0,03     0,02            0,01

\(m_{Fe}=0,03.56=1,68\left(g\right);V_{O_2}=0,02.22,4=0,448\left(l\right)\)

3Fe+2O₂-to>Fe₃O₄

0,03-----0,02-------0,01 mol

n F_e3O4=\(\dfrac{2,32}{232}\)=0,01 mol

=>m _Fe=0,03.56=1,68g

=>V O₂=0,2.22,4=0,448l

bài 2

4P+5O₂-to>2P₂O₅

  0,2---------------0,1

n _P=\(\dfrac{6,2}{31}\)=0,2 mol

n _O2=\(\dfrac{6,72}{22,4}\)=0,3 mol

=>O2 dư , P hết

=>m _P2O5= 0,1.142=14,2g