PTHH: \(2Al\left(OH\right)_3+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+6H_2O\)

Ta có: \(n_{Al\left(OH\right)_3}=\dfrac{7,8}{78}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{H_2SO_4}=0,15mol\\n_{Al_2\left(SO_4\right)_3}=0,05mol\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{H_2SO_4}=0,15\cdot98=14,7\left(g\right)\\m_{Al_2\left(SO_4\right)_3}=0,05\cdot342=17,1\left(g\right)\end{matrix}\right.\)

\(a)n_{H_2}=\dfrac{14,874}{24,79}=0,6mol\\2 Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

0,4mol     0,6mol          0,2mol           0,6mol

\(m_{Al}=0,4.27=10,8g\\ b)m_{Al_2\left(SO_4\right)_3}=0,2.342=68,4g\\ c)m_{H_2SO_4}=0,6.98=58,8g\)

nAl = 5.4/27 = 0.2 mol 

2Al + 3H2SO4 => Al2(SO4)3 + 3H2 

0.2______________0.1________0.3 

VH2 = 0.3*22.4 = 6.72 (l) 

mAl2(SO4)3 = 0.1*342 = 34.2 g 

\(n_{Al}=\dfrac{2,7}{27}=0,1mol\)

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

0,1         0,15                                0,15   ( mol )

\(V_{H_2}=0,15.22,4=3,36l\)

\(m_{H_2SO_4}=0,15.98=14,7g\)

2Al+3H2SO4->al2(SO4)3+3H2

Fe+H2SO4->FeSO4+H2

Gọi x,y tương ứng là số mol của Al và Fe:

Ta có: 27x+56y=11 (1)

nH2=0,4 mol

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

Giải hệ(1),(2):x=0,2;y=0,1

mAl=0,2.27=5,4g

%Al=\(\dfrac{5,4.100}{16,6}\)=32,53%

=>%Fe=67,47%

m H2SO4=0,4.98=39,2g

c) m muối=0,1.342+0,1.152=49,4g

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

Ta có: \(n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{H_2SO_4}=0,15\left(mol\right)=n_{H_2}\\n_{Al_2\left(SO_4\right)_3}=0,05\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{H_2SO_4}=0,15\cdot98=14,7\left(g\right)\\m_{Al_2\left(SO_4\right)_3}=0,05\cdot342=17,1\left(g\right)\\V_{H_2}=0,15\cdot22,4=3,36\left(l\right)\end{matrix}\right.\)

a) \(n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\)

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

______0,1--->0,15-------->0,05------->0,15

=> m_H2SO4 = 0,15.98 = 14,7 (g)

b) V_H2 = 0,15.22,4 = 3,36 (l)

c) m_Al2(SO4)3 = 0,05.342 = 17,1 (g)

Ta có: \(n_{H_2}=\dfrac{74,37}{24,79}=3\left(mol\right)\)

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

a, \(n_{Al}=\dfrac{2}{3}n_{H_2}=2\left(mol\right)\)

\(\Rightarrow m_{Al}=2.27=54\left(g\right)\)

b, \(n_{H_2SO_4}=n_{H_2}=3\left(mol\right)\)

\(\Rightarrow m_{H_2SO_4}=3.98=294\left(g\right)\)

\(n_{Al2O3}=\dfrac{20,4}{102}=0,2\left(mol\right)\)

Pt : \(Al_2O_3+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2O|\)

          1              3                    1                3

        0,2           0,6                   0,2

\(n_{H2SO4}=\dfrac{0,2.3}{1}=0,6\left(mol\right)\)

⇒ \(m_{H2SO4}=0,6.98=58,8\left(g\right)\)

\(n_{Al2\left(SO4\right)3}=\dfrac{0,6.1}{3}=0,2\left(mol\right)\)

⇒ \(m_{Al2\left(SO4\right)3}=0,2.342=68,4\left(g\right)\)

 Chúc bạn học tốt

\(n_{Al}=\dfrac{5,4}{27}=0,2mol\)

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

0,2                            0,1                0,3  ( mol )

\(m_{Al_2\left(SO_4\right)_3}=0,1.342=34,2g\)

\(V_{H_2}=0,3.22,4=6,72l\)