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

b) \(n_{H_2}=\dfrac{0,672}{22,4}=0,03\left(mol\right)\)

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

_____0,02<---0,03<---------------------0,03

=> \(\left\{{}\begin{matrix}\%Al=\dfrac{0,02.27}{2,16}.100\%=25\%\\\%Cu=100\%-25\%=75\%\end{matrix}\right.\)

c) m_H2SO4 = 0,03.98 = 2,94 (g)

=> \(C\%\left(H_2SO_4\right)=\dfrac{2,94}{200}.100\%=1,47\%\)

\(a.Zn+H_2SO_4\rightarrow ZnSO_4+H_2\\ b.n_{H_2}=\dfrac{4,48}{22,4}-0,2mol\\ n_{Zn}=n_{H_2SO_4}=n_{H_2}=0,2mol\\ \%m_{Zn}=\dfrac{0,2.65}{19,4}\cdot100=67,01\%\\ \%m_{Cu}=100-67,01=32,99\%\\ m_{ddH_2SO_4}=\dfrac{0,2.98}{20}\cdot100=98g\)

\(a)n_{H_2}=\dfrac{2,24}{22,4}=0,1mol\\ Zn+2HCl\rightarrow ZnCl_2+H_2\\ n_{Zn}=n_{H_2}=n_{ZnCl_2}=0,1mol\\ m_{Zn}=0,1.65=6,5g\\ m_{Cu}=9,7-6,5=3,2g\\ b)C_{\%ZnCl_2}=\dfrac{0,1.136}{6,5+120-0,1.2}\cdot100=10,77\%\)

a, \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)

\(n_{H2}=0,2\left(mol\right)=n_{Zn}=n_{H2SO4}=n_{ZnSO4}\)

\(\Rightarrow m_{Zn}=0,2.65=13\left(g\right)\)

\(\Rightarrow m_{Cu}=26-13=13\left(g\right)\)

b,\(m=\frac{0,2.98.100}{25}=78,4\left(g\right)\)

c,

\(m_{dd_{spu}}=13+78,4-0,2.2=91\left(g\right)\)

\(n_{Ba}=0,3\left(mol\right)\)

\(Ba+2H_2O\rightarrow Ba\left(OH\right)_2+H_2\)

\(\Rightarrow\) Tạo 0,3 mol Ba(OH)2; 0,3 mol H2

\(Ba\left(OH\right)_2+ZnSO_4\rightarrow BaSO_4+Zn\left(OH\right)_2\)

\(\Rightarrow\) Dư 0,1 mol Ba(OH)2. Tạo 0,2 mol BaSO4; 0,2 mol Zn(OH)2

\(Ba\left(OH\right)_2+Zn\left(OH\right)_2\rightarrow BaZnO_2+2H_2O\)

\(\Rightarrow\) Tạo 0,1 mol BaZnO2, dư 0,1 mol Zn(OH)2

Sau các phản ứng tạo 0,1 mol chất tan BaZnO2 và các chất rắn: BaSO4 (0,2 mol), Zn(OH)2 (0,1 mol)

\(m_{dd_{spu}}=m_{Ba}+91-m_{BaSO4}-m_{Zn\left(OH\right)2}-m_{H2}=75,3\left(g\right)\)

\(C\%_{BaZnO2}=\frac{0,1.234.100}{75,3}=31,08\%\)

Cảm ơn anh chị nhiều

n_H2 = \(\dfrac{4,48}{22,4}\)= 0,2 (mol)

a, Fe + 2HCl ----> FeCl₂ + H₂

0,2 0,4 0,2 (mol)

=> m_Fe = 0,2.56 = 11,2 (g)

b, => %Fe = \(\dfrac{11,2.100\%}{16}\)= 70%

=> %Cu = 100 - 70 = 30%

c, V_HCl = \(\dfrac{0,4}{2}\) = 0,2 (l)

a)

$Fe + 2HCl \to FeCl_2 + H_2$
b)

Theo PTHH : $n_{Fe} = n_{H_2} = \dfrac{4,48}{22,4} = 0,2(mol)$
$\Rightarrow m_{Fe} = 0,2.56 = 11,2(gam)$
$\Rightarrow m_{Cu} = 15,6 - 11,2  = 4,4(gam)$

\(n_{Fe} = a(mol) ; n_{Mg} = b(mol)\\ \Rightarrow 56a + 24b = 16,8 - 6,4 = 10,4(1)\\ Fe + 2HCl \to FeCl_2 + H_2\\ Mg + 2HCl \to MgCl_2 + H_2\\ n_{H_2} = a + b = \dfrac{6,72}{22,4} = 0,3(2)\)

Từ (1)(2) suy ra: a = 0,1 ; b = 0,2

Vậy :

\(\%m_{Fe} = \dfrac{0,1.56}{16,8}.100\% = 33,33\%\\ \%m_{Mg} = \dfrac{0,2.24}{16,8}.100\% = 28,57\%\\ \%m_{Cu} = 100\% - 33,33\% - 28,57\% = 38,1\%\)

Ta có: 

n H2 = 0,05 ( mol )

1.PTHH

Fe + H2SO4 ====> FeSO4 + H2

FeO + H2SO4 ====> FeSO4 + H2O

theo pthh: n Fe = n H2 = 0,05 ( mol )

=> m Fe = 2,8 ( g )

=> m FeO = 7,2 ( g ) => n FeO = 0,1 ( mol )

2.

theo pthh: n H2SO4 = 0,05 + 0,1 = 0,15

  => m H2SO4 = 14,7 ( g )

  => m dd H2SO4 9,8% = 150 ( g )

\(n_{HCl}=2.0,4=0,8(mol)\\ n_{Fe}=x(mol);n_{Al}=y(mol)\\ \Rightarrow 56x+27y=11(1)\\ Fe+2HCl\to FeCl_2+H_2\\ 2Al+6HCl\to 2AlCl_3+3H_2\\ \Rightarrow 2x+3y=0,8(2)\\ (1)(2)\Rightarrow x=0,1(mol);y=0,2(mol)\)

\(a,\Sigma n_{H_2}=x+1,5y=0,4(mol)\\ \Rightarrow V_{H_2}=0,4.22,4=8,96(l)\\ b,m_{Fe}=0,1.56=5,6(g);m_{Al}=0,2.27=5,4(g)\\ c,m_{dd_{HCl}}=400.1,12=448(g)\\ n_{FeCl_2}=0,1(mol);n_{AlCl_3}=0,2(mol)\\ \Rightarrow C\%_{FeCl_2}=\dfrac{0,1.127}{5,6+448-0,1.2}.100\%=2,8\%\\ C\%_{AlCl_3}=\dfrac{0,2.133,5}{5,4+448-0,3.2}.100\%=5,9\%\)