\(m_{Cu}=12g\Rightarrow n_{Cu}=\dfrac{12}{64}=0,1875mol\)

\(\Rightarrow m_{Fe}=m_{kl}-m_{Cu}=24-12=12g\Rightarrow n_{Fe}=\dfrac{3}{14}mol\)

\(CuO+H_2\rightarrow Cu+H_2O\)

           \(\dfrac{12}{64}\)      \(\dfrac{12}{64}\)

\(Fe_2O_3+3H_2\rightarrow2Fe+3H_2O\)

              \(\dfrac{9}{28}\)         \(\dfrac{3}{14}\)

\(\Rightarrow\Sigma n_{H_2}=\dfrac{12}{64}+\dfrac{9}{28}=\dfrac{57}{112}mol\)

\(\Rightarrow V_{H_2}=\dfrac{57}{112}\cdot22,4=11,4l\)

a, PT: \(Fe_2O_3+3H_2\rightarrow2Fe+3H_2O\)

\(CuO+H_2\underrightarrow{t^o}Cu+H_2O\)

b, Theo PT: \(n_{H_2}=n_{H_2O}=a\left(mol\right)\)

Theo ĐLBT KL, có: m _oxit + m_H2 = m_KL + m_H2O

⇒ 24 + 2a = 17,6 + 18a ⇒ a = 0,4 (mol)

\(\Rightarrow V_{H_2}=0,4.22,4=8,96\left(l\right)\)

c, Gọi: \(\left\{{}\begin{matrix}n_{Fe_2O_3}=x\left(mol\right)\\n_{CuO}=y\left(mol\right)\end{matrix}\right.\) ⇒ 160x + 80y = 24 (1)

Theo PT: \(\left\{{}\begin{matrix}n_{Fe}=n_{Fe_2O_3}=2x\left(mol\right)\\n_{Cu}=n_{CuO}=y\left(mol\right)\end{matrix}\right.\) ⇒ 56.2x + 64y = 17,6 (2)

Từ (1) và (2) ⇒ x = y = 0,1 (mol)

\(\Rightarrow\left\{{}\begin{matrix}m_{Fe_2O_3}=0,1.160=16\left(g\right)\\m_{CuO}=0,1.80=8\left(g\right)\end{matrix}\right.\)

d, \(\left\{{}\begin{matrix}\%m_{Fe_2O_3}=\dfrac{16}{24}.100\%\approx66,67\%\\\%m_{CuO}\approx33,33\%\end{matrix}\right.\)

a, PT: \(2Cu+O_2\underrightarrow{t^o}2CuO\)

\(3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\)

\(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)

\(CuO+H_2\underrightarrow{t^o}Cu+H_2O\)

\(Fe_3O_4+4H_2\underrightarrow{t^o}3Fe+4H_2O\)

Gọi: \(\left\{{}\begin{matrix}n_{Cu}=x\left(mol\right)\\n_{Fe}=y\left(mol\right)\\n_{Al}=z\left(mol\right)\end{matrix}\right.\) ⇒ 64x + 56y + 27z = 40,4 (1)

Theo PT: \(\left\{{}\begin{matrix}n_{CuO}=n_{Cu}=x\left(mol\right)\\n_{Fe_3O_4}=\dfrac{1}{3}n_{Fe}=\dfrac{1}{3}y\left(mol\right)\\n_{Al_2O_3}=\dfrac{1}{2}n_{Al}=\dfrac{1}{2}z\left(mol\right)\end{matrix}\right.\)

⇒ 80x + 232.1/3x + 102.1/2z = 59,6 (2)

- Chất rắn A gồm: Cu, Fe và Al₃O₃.

⇒ 64x + 56y + 102.1/2z = 50 (3)

Từ (1), (2) và (3) \(\Rightarrow\left\{{}\begin{matrix}x=0,2\left(mol\right)\\y=0,3\left(mol\right)\\z=0,4\left(mol\right)\end{matrix}\right.\)

⇒ m_Cu = 0,2.64 = 12,8 (g)

m_Fe = 0,3.56 = 16,8 (g)

m_Al = 0,4.27 = 10,8 (g)

b, Theo PT: \(n_{H_2}=n_{Cu}+\dfrac{4}{3}n_{Fe}=0,6\left(mol\right)\)

\(\Rightarrow V_{H_2}=0,6.22,4=13,44\left(l\right)\)

$n_{H_2} = \dfrac{6,72}{22,4} = 0,3(mol)$
$n_{Fe_2O_3} = \dfrac{40}{160} = 0,25(mol)$
$Fe_2O_3 + 3H_2 \xrightarrow{t^o} 2Fe + 3H_2O$

$n_{Fe_2O_3} : 1 = 0,25 > n_{H_2} : 3 = 0,1$ nên $Fe_2O_3$ dư

$n_{Fe} = \dfrac{2}{3}n_{H_2} = 0,2(mol)$
$n_{Fe_2O_3\ pư} = \dfrac{1}{3}n_{H_2} = 0,1(mol)$

$n_{Fe_2O_3\ dư} = 0,25 - 0,1 = 0,15(mol)$

Suy ra : 

$\%m_{Fe} = \dfrac{0,1.56}{0,1.56 + 0,15.160}.100\% = 18,92\%$

Dung dịch Ca(OH)₂ không hấp thụ khí CO nên 6,72 lít khí thoát ra chính là khí CO dư.

2.

Số mol CuO là: \(n_{CuO}=\frac{m}{M}=\frac{40}{80}=0,5\left(mol\right)\)

\(PTHH:CuO+CO\rightarrow Cu+CO_2\uparrow\)

\(\left(mol\right)\) \(1\) \(1\) \(1\) \(1\)

\(\left(mol\right)\) \(0,5\) \(0,5\) ​\(0,5\)​​​ ​​ \(0,5\)

Ta có: \(H=\frac{n_{TT}}{n_{LT}}\Leftrightarrow n_{TT}=n_{LT}.H=0,5.90\%=0,45\left(mol\right)\)

Khối lượng Cu thu được là:

\(m_{Cu}=n.M=0,45.64=28,8\left(g\right)\)

Gọi CT oxit sắt là FexOy

Gọi nCu=a(mol)

nH2=\(\dfrac{6,72}{22,4}\)=0,3(mol)

FexOy+yH2to→xFe+yH2O(1)

Fe+2HCl→FeCl2+H2(2)

Theo pthh(2) 

nFe=nH2=0,3(mol)

Theo pthh(1)

nFexOy=\(\dfrac{0,3}{x}\)(mol)

Ta có: 64a+56.0,3=29,6

⇒a=0,2(mol)

⇒mCu=0,2.64=12,8(g)

⇒mFexOy=36−12,8=23,2(g)

=>MFexOy= \(\dfrac{\dfrac{23,2}{0,3}}{x}\)=\(\dfrac{232x}{3}\)

=>56x+16y=\(\dfrac{232x}{3}\)

=>\(\dfrac{64x}{3}=16y\)

->\(\dfrac{x}{y}=\dfrac{3}{4}\)

⇒CTHH:Fe3O4

Ta có :

%m Cu=\(\dfrac{12,8}{36}100\)=35,56%

=>%m Fe3O4=100%-35,56%=64,44%

a) \(n_{H_2}=\dfrac{1,344}{22,4}=0,06\left(mol\right)\)

\(n_{Cl}=n_{HCl}=2n_{H_2}=2.0,06=0,12\left(mol\right)\)

m=m_{kim loại}+m_Cl=1,965+0,12.35,5=6,225(gam)

b) \(H_2+CuO\overset{t^0}{\rightarrow}Cu+H_2O\left(1\right)\)

\(yH_2+Fe_xO_y\overset{t^0}{\rightarrow}xFe+yH_2O\left(2\right)\)

Fe+H₂SO₄\(\rightarrow FeSO_4+H_2\left(3\right)\)

\(m_{Cu}=1,28\left(g\right)\rightarrow n_{Cu}=\dfrac{1,28}{64}=0,02\left(mol\right)\)

-Theo(1): \(n_{H_2\left(1\right)}=n_{CuO}=n_{Cu}=0,02\left(mol\right)\)

\(\rightarrow m_{CuO}=0,02.80=1,6\left(g\right)\rightarrow m_{Fe_xO_y}=3,92-1,6=2,32\left(g\right)\)

\(\rightarrow n_{H_2\left(2\right)}=n_{H_2}-n_{H_2\left(1\right)}=0,06-0,02=0,04\left(mol\right)\)

-Theo(2): \(n_{Fe_xO_y}=\dfrac{1}{y}n_{H_2}=\dfrac{0,04}{y}mol\rightarrow M_{Fe_xO_y}=\dfrac{2,32}{\dfrac{0,04}{y}}=58y\)

\(\rightarrow56x+16y=58y\rightarrow56x=42y\rightarrow\dfrac{x}{y}=\dfrac{42}{56}=\dfrac{3}{4}\)

\(\rightarrow Fe_3O_4\)

%CuO=\(\dfrac{1,6}{3,92}.100\approx40,8\%\)

%Fe₃O₄=100%-40,8%=59,2%