\(1) Fe_2O_3 + 3H_2 \xrightarrow{t^o} 2Fe + 3H_2O\\ Fe_3O_4 + 4H_2 \xrightarrow{t^o} 3Fe + 4H_2O \text{Theo PTHH }\\ n_{H_2O} = n_{H_2} = \dfrac{20,16}{22,4}=0,9(mol)\\ \text{Bảo toàn khối lượng : }\\ a = m_{hh} + m_{H_2} - m_{H_2O} = 65,4 + 0,9.2 - 0,9.18 = 51(gam)\)

2)

\(n_{Mg} = a ; n_{Al} = b ; n_{Fe} = c\\ \Rightarrow 24a + 27b + 56c = 18,6(1)\\ Mg + 2HCl \to MgCl_2 + H_2\\ 2Al + 6HCl \to 2AlCl_3 + 3H_2\\ Fe + 2HCl \to FeCl_2 + H_2\\ n_{H_2} = a + 1,5b + c = \dfrac{14,56}{22,4}=0,65(2)\\ 2Mg + O_2 \xrightarrow{t^o} 2MgO\\ 4Al + 3O_2 \xrightarrow{t^o} 2Al_2O_3\\ 3Fe + 2O_2 \xrightarrow{t^o} Fe_3O_4\\ n_{O_2} = \dfrac{7,84}{22,4} = 0,35\)

Ta có :

\(\dfrac{a + b + c}{0,5a + 0,75b + \dfrac{2}{3}c} = \dfrac{0,55}{0,35}(3)\\ (1)(2)(3) \Rightarrow a = 0,2 ; b = 0,2 ; c= 0,15\\ \%m_{Mg} = \dfrac{0,2.24}{18,6}.100\% = 25,81\%\\ \%m_{Al} = \dfrac{0,2.27}{18,6}.100\% = 29,03\%\\ \%m_{Fe} = 100\% - 25,81\% -29,03\% = 45,16\%\)

a) \(Pt:Fe+H_2SO_4\rightarrow FeSO_4+H_2\)

b) \(n_{Fe}=\dfrac{0,56}{56}=0,01mol\)

Theo pt: \(n_{FeSO_4}=n_{Fe}=0,01mol\)

\(\Rightarrow m_{FeSO_4}=0,01.152=1,52g\)

Theo pt: \(n_{H_2}=n_{Fe}=0,01mol\)

\(\Rightarrow V_{H_2}=0,01.22,4=0,224lít\)

c) \(Theopt:nH_2SO_4=n_{Fe}=0,01mol\)

\(\Rightarrow m_{H_2SO_4}=0,01.98=0,98g\)

\(\Rightarrow m_{ddH_2SO_4}=\dfrac{0,98.100}{19,6}=5g\)

1) Fe + H₂SO₄ --> FeSO₄ + H₂

2) Zn + 2HCl --> ZnCl₂ + H₂

3) 2Al + 3H₂SO₄ --> Al₂(SO₄)₃ + 3H₂

4) Zn + H₂SO₄ --> ZnSO₄ + H₂

5) Mg + 2HCl --> MgCl₂ + H₂

6) H₂ + CuO --t^o--> Cu + H₂O

7) 2H₂ + O₂ --t^o--> 2H₂O

`->` Đáp án + Giải thích:

1) Fe + H₂SO₄ --> FeSO₄ + H₂

2) Zn + 2HCl --> ZnCl₂ + H₂

3) 2Al + 3H₂SO₄ --> Al₂(SO₄)₃ + 3H₂

4) Zn + H₂SO₄ --> ZnSO₄ + H₂

5) Mg + 2HCl --> MgCl₂ + H₂

6) H₂ + CuO --t^o--> Cu + H₂O

7) 2H₂ + O₂ --t^o--> 2H₂O

1 ) Fe + H2SO4 ---> FeSO4 + H2 
2 ) Zn+2HCl ---> ZnCl2 + H2 
3 ) 2Al + 3H2SO4 l ---> Al2(SO4)3 +3H2
4) Zn + H2SO4 --> ZnSO4 +H2 
5) Mg + 2HCl --> MgCl2 + H2 
6 ) H2 +CuO -t---> Cu +H2O 
7 ) 2H2 + O2 -----> 2H2O

Bài 1:

H2 + O2 → H2O

N2O5 + H2O → HNO3

Bài 4:

Fe2(SO3)3: Sắt III sunfat 

Mg(OH)2: Magie hidroxit

H3PO4: axit photphoric

Ba(HSO4)2: Bari Bisunfat 

Bài 1 : 

\(a.2H_2+O_2\underrightarrow{^{t^0}}2H_2O\)

\(b.N_2O_5+H_2O\rightarrow2HNO_3\)

Bài 2 : 

\(n_{Al}=\dfrac{5.4}{27}=0.2\left(mol\right)\)

\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

\(0.2............0.3...........0.1..............0.3\)

\(m_{H_2SO_4}=0.3\cdot98=29.4\left(g\right)\)

\(m_{Al_2\left(SO_4\right)_3}=0.1\cdot342=34.2\left(g\right)\)

\(m_{H_2}=0.3\cdot2=0.6\left(g\right)\)

\(V_{H_2}=0.3\cdot22.4=6.72\left(l\right)\)

Bài 3 : 

\(n_{A\left(OH\right)_n}=0.2\cdot1=0.2\left(mol\right)\)

\(2A+2nH_2O\rightarrow2A\left(OH\right)_n+nH_2\)

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

\(M_A=\dfrac{8}{0.2}=40\left(\dfrac{g}{mol}\right)\)

\(A:Canxi\:\)

Bài 4 : 

Fe₂(SO₄)₃ : Sắt (III) sunfat 

Mg(OH)₂ : Magie hidroxit

H₃PO₃: Axit photphoro

Ba(HSO₄)₂: Bari hidrosunfat

2Al+3H2SO4--->Al2(SO4)3+3H2

Zn+H2SO4--->ZnSO4+H2

Gọi n Al=x----->m Al=27x(g)

n Zn=y--->m Zn=65y(g)

-->27x+65y=11,9(1)

Mặt khác: n H2=8,96/22,4=0,4(mol)

Theo pthh1

n H2=3/2n Al=1,5x(mol)

Theo pthh2

n H2=n Zn=y(mol)

-->1,5x+y=0,4(2)

Từ 1 và 2 ta có hpt

\(\left\{{}\begin{matrix}27x+65y=11,9\\1,5x+y=0,4\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,2\\y=0,1\end{matrix}\right.\)

%m Al=0,2.27/11,9.100%=45,38%

%m Zn=100%-45,38%=54,62%

help me

a) Gọi số mol Al, Zn là a, b (mol)

=> 27a + 65b = 11,9 (1)

\(n_{H_2}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\)

PTHH: 2Al + 3H₂SO₄ --> Al₂(SO₄)₃ + 3H₂

             a----->1,5a----------------->1,5a

            Zn + H₂SO₄ --> ZnSO₄ + H₂

             b------>b------------------>b

=> 1,5a + b = 0,4 (2)

(1)(2) => a = 0,2 (mol); b = 0,1 (mol)

\(\left\{{}\begin{matrix}\%m_{Al}=\dfrac{0,2.27}{11,9}.100\%=45,378\%\\\%m_{Zn}=\dfrac{0,1.65}{11,9}.100\%=54,622\%\end{matrix}\right.\)

b) n_H2SO4 = 1,5a + b = 0,4 (mol)

=> m_H2SO4 = 0,4.98 = 39,2 (g)

=> \(C\%_{dd.H_2SO_4}=\dfrac{39,2}{150}.100\%=26,133\%\)

\(n_{H_2}=\dfrac{33,6}{22,4}=1,5\left(mol\right)\\ m_{H_2}=1,5.2=3\left(g\right)\)

PTHH : 2Al + H₂SO₄ -> Al₂SO₄ + H₂

Theo ĐLBTKL

\(m_{Al}+m_{H_2SO_4}=m_{Al_2SO_4}+m_{H_2}\\ \Rightarrow m_{H_2SO_4}=\left(171+3\right)-2,7=171,3\left(g\right)\)

Em coi lại đề bài nhé! 0,1 mol nhôm không thể tạo ra được 0,5mol muối nhôm sunfat và 1,5 mol khí hidro

Các bạn dưới làm chắc không để ý đề bài!

pthh: 2Al+3H\(_2\)SO\(_4\)→Al\(_2\)(SO4)\(_3\)+3H\(_2\)↑

nH\(_2=33,6:22,4=1,5\left(mol\right)\)

\(mH_2=1,5.2=3\left(g\right)\)

\(nAl_2\left(SO_4\right)=171:150=1,14\left(mol\right)\)

\(mAl_2\left(SO_4\right)_3=1,14.342=389,88\left(g\right)\)

BTKL : mAl + mH\(_2\)SO\(_4\) = m Al\(_2\)(SO4)\(_3\)  + m H\(_2\)

           2,7    +  mH\(_2\)SO\(_4\) =  389,88       +   3

=> \(mH_2SO_4=\left(389,88+3\right)-2,7=390,18\left(g\right)\)