Cu ko phản ứng với H2SO4 loãng

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

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

\(\Rightarrow m_{Zn}=0,1.65=6,5\left(g\right)\Rightarrow m_{Cu}=4\left(g\right)\)

\(\Rightarrow\%Zn=\dfrac{6,5}{10,5}=62\%;\%Cu=100\%-62\%=28\%\)

https://hoidap247.com/cau-hoi/1072966

Gọi a=nCu; b=nZn

Ta có 64a+65b=15,75 (1)

Zn+H2ZO4-> ZnSO4+H2

b.                                     b

 b=nH2= 3,36/22,4=0,15mol

mZn= 0,15.65= 9,75g

mCu=15,75-9,75=6(g)

%mZn=9,75.100%/15,75 =61,9%

%mCu=6.100%/15,75*38,1%

Z n + H 2 S O 4 → Z n S O 4 + H 2

Cu không tác dụng với axit Sunfuric.

⇒ n Z n = n H 2 = 2,24/22,4 = 0,1 mol

⇒ m Z n = 0,1.65 = 6,5g

⇒ m C u = m r a n   c o n   l a i  = 10,5 - 6,5 =4g

⇒ Chọn B.

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

\(Cu+2H_2SO_{4\left(đ\right)}\underrightarrow{t^o}CuSO_4+SO_2+2H_2O\)

b, Ta có: \(n_{H_2}=\dfrac{2,479}{24,79}=0,1\left(mol\right)\)

\(n_{Zn}=n_{H_2}=0,1\left(mol\right)\)

\(n_{SO_2}=\dfrac{2,9748}{24,79}=0,12\left(mol\right)\)

\(n_{Cu}=n_{SO_2}=0,12\left(mol\right)\)

\(\Rightarrow m=m_{Zn}+m_{Cu}=0,1.65+0,12.64=14,18\left(g\right)\)

Có: \(n_{H_2SO_{4\left(đ\right)}}=2n_{SO_2}=0,24\left(mol\right)\Rightarrow x=m_{ddH_2SO_4\left(đ\right)}=\dfrac{0,24.98}{98\%}=24\left(g\right)\)

Bảo toàn nguyên tố: \(n_{H_2SO_4}=n_{H_2}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}m_{H_2}=0,5\cdot2=1\left(g\right)\\m_{H_2SO_4}=0,5\cdot98=49\left(g\right)\end{matrix}\right.\)

Bảo toàn khối lượng: \(m_{muối}=m_{KL}+m_{H_2SO_4}-m_{H_2}=68,2\left(g\right)\)

\(Zn + H_2SO_4 \to ZnSO_4 + H_2\\ Mg + H_2SO_4 \to MgSO_4 + H_2\\ n_{H_2SO_4} = n_{H_2} = \dfrac{11,2}{22,4} = 0,5(mol)\\ m_{muối} = m_{hh} + m_{H_2SO_4} - m_{H_2} = 20,2 + 0,5.98 - 0,5.2 = 68,2(gam)\)

\(n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)

PTHH: Fe + H₂SO₄ --> FeSO₄ + H₂

_____0,15<--------------0,15<---0,15

=> m_Fe = 0,15.56 = 8,4 (g)

=> m_Cu = 11,6 - 8,4 = 3,2 (g)

\(\left\{{}\begin{matrix}\%Fe=\dfrac{8,4}{11,6}.100\%=72,414\%\\\%Cu=\dfrac{3,2}{11,6}.100\%=27,586\%\end{matrix}\right.\)

m_FeSO4 = 0,15.152 = 22,8 (g)

\(a) Zn + H_2SO_4 \to ZnSO_4 + H_2\\ ZnO + H_2SO_4 \to ZnSO_4 + H_2O\\ n_{Zn} = n_{H_2} = \dfrac{4,48}{22,4} = 0,2(mol)\\ \%m_{Zn} = \dfrac{0,2.65}{17,05}.100\% = 76,25\%\\ \%m_{ZnO} = 100\% -76,25\% = 23,75\%\\ b) n_{Ba(NO_3)_2}= 0,2.1,5 = 0,3(mol)\ ; n_{ZnO} = \dfrac{17,05-0,2.65}{81} = 0,05(mol)\\ n_{ZnSO_4} = n_{Zn} + n_{ZnO} = 0,25(mol)\\ ZnSO_4 + Ba(NO_3)_2 \to BaSO_4 + Zn(NO_3)_2\\ n_{ZnSO_4} < n_{Ba(NO_3)_2} \to Ba(NO_3)_2\ dư\\ \)

\(n_{BaSO_4} = n_{ZnSO_4} = 0,25(mol)\\ m_{BaSO_4} = 0,25.233 = 58,25(gam)\)

a) \(n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)

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

           0,1<----------------------------0,15

=> \(\%m_{Al}=\dfrac{0,1.27}{7,5}.100\%=36\%\)

\(\%m_{Cu}=100\%-36\%=64\%\)

b) \(n_{Cu}=\dfrac{7,5-0,1.27}{64}=0,075\left(mol\right)\)

PTHH: Cu + 2H₂SO₄ --> CuSO₄ + SO₂ + 2H₂O

          0,075------------------------>0,075

            2Al + 6H₂SO₄ --> Al₂(SO₄)₃ + 3SO₂ + 6H₂O

              0,1----------------------------->0,15

=> V_SO2 = (0,075 + 0,15).22,4 = 5,04 (l)