a. \(PTHH:3H_2+Fe_2O_3\rightarrow2Fe+3H_2O\)

b. \(n_{Fe_2O_3}=\dfrac{m_{Fe_2O_3}}{M_{Fe_2O_3}}=\dfrac{40}{160}=0,25\left(mol\right)\)

- Mol theo PTHH : \(3:1:2:3\)

- Mol theo phản ứng : \(0,75\leftarrow0,25\rightarrow0,5\rightarrow0,75\)

\(\Rightarrow n_{Fe}=0,5\left(mol\right)\)

\(\Rightarrow m_{Fe}=n_{Fe}.M_{Fe}=0,5.56=28\left(g\right)\)

c. Ta có : \(n_{Fe_2O_3}=0,25\left(mol\right);n_{H_2}=0,3\left(mol\right)\)

Do \(0,25< 0,3\) ⇒ H₂ dư.

a, PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)

b, Ta có: \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)

Theo PT: \(n_{H_2}=n_{Zn}=0,1\left(mol\right)\Rightarrow V_{H_2}=0,1.22,4=2,24\left(l\right)\)

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

Theo PT: \(n_{Fe}=\dfrac{2}{3}n_{H_2}=\dfrac{1}{15}\left(mol\right)\Rightarrow m_{Fe}=\dfrac{1}{15}.56=\dfrac{56}{15}\left(g\right)\)

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

b, \(n_{Fe}=\dfrac{24}{56}=\dfrac{3}{7}\left(mol\right)\)

Theo PT: \(n_{Fe_2O_3}=\dfrac{1}{2}n_{Fe}=\dfrac{3}{14}\left(mol\right)\Rightarrow m_{Fe_2O_3}=\dfrac{3}{14}.160=\dfrac{240}{7}\left(g\right)\)

c, Theo PT: \(n_{H_2}=\dfrac{3}{2}n_{Fe}=\dfrac{9}{14}\left(mol\right)\Rightarrow V_{H_2}=\dfrac{9}{14}.22,4=14,4\left(l\right)\)

\(n_{Fe}=\dfrac{m}{M}=\dfrac{24}{56}\approx0,43\left(mol\right)\\ a.PTHH:Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\)  

                     2             3         2          3

                   0,43      0,645   0,45     0,645

\(b.m_{Fe_2O_3}=n.M=0,43.\left(56.2+16.3\right)=68,8\left(g\right)\\ c.V_{H_2}=n.24,79=0,645.24,79=15,98955\left(l\right).\)

a)\(PTHH:Fe_3O_4+4H_2\xrightarrow[]{}3Fe+4H_2O\)

b)\(m_{Fe}=\dfrac{24}{56}=0,4\left(m\right)\)

\(PTHH:Fe_3O_4+4H_2\xrightarrow[]{}3Fe+4H_2O\)

tỉ lệ       :1              4           3         4

số mol  :0,13         0,53       0,4     0,53

\(m_{Fe_3O_4}=0,13.232=30,16\left(g\right)\)

c)\(V_{H_2}=0,53.22,4=11,872\left(l\right)\)

a) \(n_{Mg}=\dfrac{6}{24}=0,25\left(mol\right)\)

PTHH: Mg + H₂SO₄ --> MgSO₄ + H₂

           0,25----------------------->0,25

=> V_H2 = 0,25.22,4 = 5,6 (l)

b) 

\(n_{Fe_2O_3}=\dfrac{32}{160}=0,2\left(mol\right)\)

PTHH: Fe₂O₃ + 3H₂ --t^o--> 2Fe + 3H₂O

Xét tỉ lệ: \(\dfrac{0,2}{1}>\dfrac{0,25}{3}\) => H₂ hết

PTHH: Fe₂O₃ + 3H₂ --t^o--> 2Fe + 3H₂O

                           0,25----->\(\dfrac{1}{6}\)

=> \(m_{Fe}=\dfrac{1}{6}.56=\dfrac{28}{3}\left(g\right)\)

\(n_{Fe_2O_3}=\dfrac{14.4}{160}=0.09\left(mol\right)\)

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

\(0.09.........0.27...0.18\)

\(V_{H_2}=0.27\cdot22.4=6.048\left(l\right)\)

\(m_{Fe}=0.18\cdot56=10.08\left(g\right)\)

PTHH: \(FeO+H_2\longrightarrow Fe+H_2O\)

a/ \(n_{FeO}=\dfrac{m_{FeO}}{M_{FeO}}=\dfrac{14,4}{72}=0,2(mol)\)

\(\to n_{H_2}=0,2(mol)\)

\(\to V_{H_2}=0,2.22,4=4,48(l)\)

b/ \(n_{Fe}=n_{H_2}=0,2(mol)\)

\(\to m_{Fe}=0,2.56=11,2(g)\)

n F e 2 O 3 = 14.4 160 = 0.09 ( m o l ) F e 2 O 3 + 3 H 2 t 0 → 2 F e + 3 H 2 O 0.09.........0.27...0.18 V H 2 = 0.27 ⋅ 22.4 = 6.048 ( l ) m F e = 0.18 ⋅ 56 = 10.08 ( g )

\(n_{Fe}=\dfrac{11.2}{56}=0.2\left(mol\right)\)

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

\(0.1.....................0.2\)

\(m_{Fe_2O_3}=0.1\cdot160=16\left(g\right)\)

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

a+b) \(n_{Fe}=\dfrac{22,4}{56}=0,4\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{Fe_2O_3}=0,2\left(mol\right)\\n_{H_2}=0,6\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{Fe_2O_3}=0,2\cdot160=32\left(g\right)\\V_{H_2}=0,6\cdot22,4=13,44\left(l\right)\end{matrix}\right.\)

c) PTHH: \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\uparrow\)

Theo PTHH: \(n_{Zn}=n_{H_2}=0,6\left(mol\right)\)

\(\Rightarrow m_{Zn}=0,6\cdot65=39\left(g\right)\)

a,

nFe = 22,4/56 = 0,4  (mol)

PTHH

Fe₂O₃ + 3H₂ ---t^o----) 2Fe + 3H₂O        (1)

theo phương trình (1) ,ta có:

nFe₂O₃ = 0,4 x 2 / 1 = 0,8 (mol)

mFe₂O₃ = 160 x 0,8 = 128 (g)

b,

theo pt (1)

nH₂ = (0,4 x 3)/2 = 0,6 (mol)

=) VH₂ = 0,6 x 22,4 = 13,44 (L)

c,

PTHH

Zn + H₂SO₄ -------------) ZnSO₄ + H₂                         (2)

Số mol H₂ cần dùng là 0,6 (mol)

Theo PT (2) :

nZn = nH₂    ==) nZn = 0,6 x 65 = 39 (g)