\(n_{H_2SO_4}=0,2.1=0,2\left(mol\right)\)

PTHH: Fe₂O₃ + 3H₂SO₄ → Fe₂(SO₄)₃ + 3H₂O

Mol:         x             3x

PTHH: CuO + H₂SO₄ → CuSO₄ + H₂O

Mol:        y           y

Ta có: \(\left\{{}\begin{matrix}160x+80y=16\\3x+y=0,2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0\\y=0,2\end{matrix}\right.\)

\(\Rightarrow\%m_{CuO}=100\%;\%m_{Fe_2O_3}=0\%\)

Thấy đề nó sai sai

\(a.Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\\ CuO+H_2SO_4\rightarrow CuSO_4+H_2O\\ b.n_{H_2SO_4}=0,22.1,25=0,275mol\\ n_{Fe_2O_3}=a;n_{CuO}=b\\ \Rightarrow\left\{{}\begin{matrix}3a+b=0,275\\160a+80b=16\end{matrix}\right.\\ \Rightarrow a=0,075;b=0,05\\ \%m_{Fe_2O_3}=\dfrac{0,075.160}{16}\cdot100=75\%\\ \%m_{CuO}=100-75=25\%\)

\(n_{FeO}=a\left(mol\right),n_{CuO}=b\left(mol\right)\)

\(m_{hh}=72a+80b=19.2\left(g\right)\left(1\right)\)

\(FeO+H_2SO_4\rightarrow FeSO_4+H_2O\)

\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)

\(n_{H_2SO_4}=a+b=0.25\left(mol\right)\left(2\right)\)

\(\left(1\right),\left(2\right):a=0.1,b=0.15\)

\(m_{FeO}=0.1\cdot72=7.2\left(g\right)\)

\(m_{CuO}=12\left(g\right)\)

\(C_{M_{FeSO_4}}=\dfrac{0.1}{0.25}=0.4\left(M\right)\)

\(C_{M_{CuSO_4}}=\dfrac{0.15}{0.25}=0.6\left(M\right)\)

Câu 1:

a, PT: \(CuO+H_2\underrightarrow{t^o}Cu+H_2O\)

\(Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\)

Giả sử: \(\left\{{}\begin{matrix}n_{CuO}=x\left(mol\right)\\n_{Fe_2O_3}=y\left(mol\right)\end{matrix}\right.\)

⇒ 80x + 160y = 40 (1)

Ta có: \(n_{H_2}=\dfrac{13,44}{22,4}=0,6\left(mol\right)\)

Theo PT: \(\Sigma n_{H_2}=n_{CuO}+3n_{Fe_2O_3}=x+3y\left(mol\right)\)

⇒ x + 3y = 0,6 (2)

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

\(\Rightarrow\left\{{}\begin{matrix}m_{CuO}=0,3.80=24\left(g\right)\\m_{Fe_2O_3}=0,1.160=16\left(g\right)\end{matrix}\right.\)

b, Ta có: \(\left\{{}\begin{matrix}\%m_{CuO}=\dfrac{24}{40}.100\%=60\%\\\%m_{Fe_2O_3}=40\%\end{matrix}\right.\)

Câu 4:

PT: \(2Na+2H_2O\rightarrow2NaOH+H_2\)

Ta có: \(n_{Na}=\dfrac{6,9}{23}=0,3\left(mol\right)\)

\(n_{H_2O}=\dfrac{150}{18}=\dfrac{25}{3}\left(mol\right)\)

Xét tỉ lệ ta được H₂O dư.

Theo PT: \(n_{NaOH}=n_{Na}=0,3\left(mol\right)\) \(\Rightarrow m_{NaOH}=0,3.40=12\left(g\right)\)

\(n_{H_2}=\dfrac{1}{2}n_{Na}=0,15\left(mol\right)\)

Ta có: m _{dd sau pư} = m_Na + m_H2O - m_H2 = 6,9 + 150 - 0,15.2 = 156,6 (g)

\(\Rightarrow C\%_{NaOH}=\dfrac{12}{156,6}.100\%\approx7,66\%\)

Bạn tham khảo nhé!

PTHH: 2Na +2H₂O →2NaOH+ H₂ ↑

\(+n_{Na}=\dfrac{6,9}{23}=0,3\left(mol\right)\)

Theo PTHH ta có: 

\(+n_{NaOH}=n_{Na}=0,3\left(mol\right)\)

\(+n_{H_2}=\dfrac{1}{2}n_{Na}=0,15\left(mol\right)\)

\(+m_{NaOH}=0,3.40=12\left(gam\right)\)

\(+C\%_{NaOH}=\dfrac{12}{150+6,9-0,15.2}.100\%\approx7,66\%\)

\(a)n_{HCl}=0,1.3=0,3mol\\ n_{CuO}=a;n_{ZnO}=b\\ CuO+2HCl\rightarrow CuCl_2+H_2O\\ ZnO+2HCl\rightarrow ZnCl_2+H_2O\\ \Rightarrow\left[{}\begin{matrix}80a+81b=12,1\\2a+2b=0,3\end{matrix}\right.\\ \Rightarrow a=0,05;b=0,1\\ \%m_{CuO}=\dfrac{80.0,05}{12,1}\cdot100=33,06\%\\ \%m_{ZnO}=100-33,06=66,94\%\\ b)ZnO+H_2SO_4\rightarrow ZnSO_4+H_2O\\ CuO+H_2SO_4\rightarrow CuSO_4+H_2O \\ n_{H_2SO_4}=0,05+0,1=0,15mol\\ m_{ddH_2SO_4}=\dfrac{0,15.98}{20}\cdot100=73,5g\)

Đổi 300ml = 0,3 lít

Ta có: \(n_{HCl}=2.0,3=0,6\left(mol\right)\)

a. PTHH: 

CuO + 2HCl ---> CuCl₂ + H₂O (1)

ZnO + 2HCl ---> ZnCl₂ + H₂O (2)

b. Gọi x, y lần lượt là số mol của CuO và ZnO

Theo PT₍₁₎: \(n_{HCl}=2.n_{CuO}=2x\left(mol\right)\)

Theo PT₍₂₎: \(n_{HCl}=2.n_{ZnO}=2y\left(mol\right)\)

=> 2x + 2y = 0,6 (*)

Theo đề, ta có: 80x + 81y = 24,2 (**)

Từ (*) và (**), ta có HPT:

\(\left\{{}\begin{matrix}2x+2y=0,6\\80x+81y=24,2\end{matrix}\right.\)

=> \(\left\{{}\begin{matrix}x=0,1\\y=0,2\end{matrix}\right.\)

=> \(m_{CuO}=0,1.80=8\left(g\right)\)

=> \(\%_{m_{CuO}}=\dfrac{8}{24,2}.100\%=33,06\%\)

\(\%_{m_{Zn}}=100\%-33,06\%=66,94\%\)

c. PTHH:

CuO + H₂SO₄ ---> CuSO₄ + H₂O (3)

ZnO + H₂SO₄ ---> ZnSO₄ + H₂O (4)

Theo PT₍₃₎: \(n_{H_2SO_4}=n_{CuO}=0,1\left(mol\right)\)

Theo PT₍₄₎: \(n_{H_2SO_4}=n_{ZnO}=0,2\left(mol\right)\)

=> \(n_{H_2SO_4}=0,1+0,2=0,3\left(mol\right)\)

=> \(m_{H_2SO_4}=0,3.98=29,4\left(g\right)\)

Ta có: \(C_{\%_{H_2SO_4}}=\dfrac{29,4}{m_{dd_{H_2SO_4}}}.100\%=20\%\)

=> \(m_{dd_{H_2SO_4}}=147\left(g\right)\)

\(n_{H_2SO_4}=0,25.2=0,5\left(mol\right)\)

Gọi \(\left\{{}\begin{matrix}n_{Al_2O_3}=x\left(mol\right)\\n_{CuO}=y\left(mol\right)\end{matrix}\right.\)

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

 x----------> 3x --------> x 

\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)

y --------> y -------->  y

Có hệ phương trình

\(\left\{{}\begin{matrix}102x+80y=26,2\\3x+y=0,5\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,1\\y=0,2\end{matrix}\right.\)

\(\%_{m_{Al_2O_3}}=\dfrac{102.0,1.100}{26,2}=38,93\%\)

\(\%_{m_{CuO}}=\dfrac{80.0,2.100}{26,2}=61,07\%\)

\(CM_{Al_2\left(SO_4\right)_3}=\dfrac{x}{0,25}=\dfrac{0,1}{0,25}=0,4M\)

\(CM_{CuSO_4}=\dfrac{y}{0,25}=\dfrac{0,2}{0,25}=0,8M\)