\(n_{H_2} = 1(mol)\)

Fe + 2HCl → FeCl₂ + H₂

1.........2.......................1.............(mol)

⇒ m_Fe = 1.56 = 56 > m_{hỗn hợp} = 21,6

(Sai đề)

a, PT: \(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)

\(Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\)

b, Ta có: \(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

Theo PT: \(n_{Fe}=n_{H_2}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}\%m_{Fe}=\dfrac{0,1.56}{21,6}.100\%\approx25,93\%\\\%m_{Fe_2O_3}\approx100-25,93=74,07\%\end{matrix}\right.\)

a, PT: 

b, Ta có: ⇒⎧⎪⎨⎪⎩%mFe=0,1.5621,6.100%≈25,93%%mFe2O3≈100−25,93=74,07%

\(Đặt:n_{Al}=a\left(mol\right),n_{Fe}=b\left(mol\right)\)

\(m_{hh}=27a+56b=8.3\left(g\right)\left(1\right)\)

\(n_{H_2}=\dfrac{5.6}{22.4}=0.25\left(mol\right)\)

\(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

\(Fe+2HCl\rightarrow FeCl_2+H_2\)

\(Tathấy:\)

\(n_{HCl}=2n_{H_2}=2\cdot0.25=0.5\left(mol\right)\)

\(V_{ddHCl}=\dfrac{0.5}{0.2}=2.5\left(l\right)\)

\(n_{H_2}=1.5a+b=0.25\left(mol\right)\left(2\right)\)

\(\left(1\right),\left(2\right):a=b=0.1\)

\(C_{M_{AlCl_3}}=\dfrac{0.1}{2.5}=0.04\left(M\right)\)

\(C_{M_{FeCl_2}}=\dfrac{0.1}{2.5}=0.04\left(M\right)\)

Chúc em học tốt !!!

a, Ta có: \(n_{H_2}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)

BTNT H, có: \(n_{HCl}=2n_{H_2}=0,5\left(mol\right)\)

\(\Rightarrow V_{HCl}=\dfrac{0,5}{0,2}=2,5\left(l\right)\)

b, Giả sử: \(\left\{{}\begin{matrix}n_{Al}=x\left(mol\right)\\n_{Fe}=y\left(mol\right)\end{matrix}\right.\)

⇒ 27x + 56y = 8,3 (1)

Các quá trình:

\(Al^0\rightarrow Al^{+3}+3e\)

x___________ 3x (mol)

\(Fe^0\rightarrow Fe^{+2}+2e\)

y____________2y (mol)

\(2H^++2e\rightarrow H_2^0\)

______0,5__0,25 (mol)

Theo ĐLBT mol e, có: 3x + 2y = 0,5 (2)

Từ (1) và (2) ⇒ x = y = 0,1 (mol)

BTNT Al và Fe, có: \(\left\{{}\begin{matrix}n_{AlCl_3}=n_{Al}=0,1\left(mol\right)\\n_{FeCl_3}=n_{Fe}=0,1\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow C_{M_{AlCl_3}}=C_{M_{FeCl_3}}=\dfrac{0,1}{2,5}=0,04M\)

Bạn tham khảo nhé!

a)

Gọi $n_{Fe} = a(mol) ; n_{Al} =b (mol) \Rightarrow 56a + 27b = 11(1)$
$Fe + 2HCl \to FeCl_2 + H_2$
$2Al + 6HCl \to 2AlCl_3 + 3H_2$
Theo PTHH : $n_{H_2} = a + 1,5b = \dfrac{8,96}{22,4} = 0,4(2)$

Từ (1)(2) suy ra : a = 0,1 ; b = 0,2

$\%m_{Fe} = \dfrac{0,1.56}{11}.100\% = 50,9\%$
$\%m_{Al} = 100\% - 50,9\% = 49,1\%$

b) $n_{HCl} = 2n_{H_2} = 0,8(mol)$
$\Rightarrow C_{M_{HCl}} = \dfrac{0,8}{0,4} = 2M$

c)

$C_{M_{FeCl_2}} = \dfrac{0,1}{0,4} = 0,25M$
$C_{M_{AlCl_3}} =\dfrac{0,2}{0,4} = 0,5M$

PTHH: \(Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)

            \(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)

a) Ta có: \(n_{H_2}=\dfrac{8,96}{22,4}=0,4\left(mol\right)=n_{Zn}\)

\(\Rightarrow\%m_{Zn}=\dfrac{0,4\cdot65}{36,2}\cdot100\%\approx71,23\%\) \(\Rightarrow\%m_{Al_2O_3}=28,77\%\)

c) Ta có: \(n_{Al_2O_3}=\dfrac{36,2-0,4\cdot65}{102}=0,1\left(mol\right)\)

Theo PTHH: \(n_{HCl}=2n_{Zn}+6n_{Al_2O_3}=1,4\left(mol\right)\)

\(\Rightarrow m_{ddHCl}=\dfrac{1,4\cdot36,5}{10\%}=511\left(g\right)\) \(\Rightarrow V_{ddHCl}=\dfrac{511}{1,1}\approx464,5\left(ml\right)=0,4645\left(l\right)\)

c) Theo PTHH: \(\left\{{}\begin{matrix}n_{ZnCl_2}=0,4\left(mol\right)\\n_{AlCl_3}=0,2\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}C_{M_{ZnCl_2}}=\dfrac{0,4}{0,4645}\approx0,86\left(M\right)\\C_{M_{AlCl_3}}=\dfrac{0,2}{0,4645}\approx0,43\left(M\right)\end{matrix}\right.\)

$a)PTHH:2Al+6HCl\to 2AlCl_3+3H_2$

$n_{H_2}=\dfrac{5,04}{22,4}=0,225(mol)$

$\Rightarrow n_{Al}=0,15(mol)$

$\Rightarrow \%m_{Al}=\dfrac{0,15.27}{9,45}.100\%\approx 42,86\%$

$\Rightarrow \%m_{Cu}=100-42,86=57,14\%$

$b)$ Theo PT: $n_{HCl}=2n_{H_2}=0,45(mol)$

$\Rightarrow C_{M_{HCl}}=\dfrac{0,45.110\%}{0,5}=0,99M$

mO2 = 31,03% . 27,84 = 8,64 (g)

nO2 = 0,135 (mol)

nH2 = 2,24/22,4 = 0,1 (mol)

PTHH: 

Al2O3 + 3H2SO4 -> Al2(SO4)3 + 3H2O (1)

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

Mg + H2SO4 -> MgSO4 + H2 (3)

Theo PTHH (1): nH2O = nH2SO4 = nO = 0,135 (mol)

Theo PTHH (2)(3): nH2 = nH2SO4 = 0,1 (mol)

mH2SO4 = (0,1 + 0,135) . 98 = 5,264 (g)

mH2O = 0,135 . 18 = 2,43 (g)

mH2 = 0,1 . 2 = 0,2 (g)

Áp dụng ĐLBTKL, ta có:

mAl + mMg + mAl2O3 + mH2SO4 = m(muối) + mH2 + mH2O

=> m(muối) = 27,84 + 5,264 - 0,2 - 2,43 = 30,474 (g)