nH2=0,4/2=0,2

a. Fe+H2SO4\(\rightarrow\)FeSO4+H2

nFe=nH2=0,2

\(\rightarrow\)%mFe=\(\frac{0,2.56}{12}\)=93,33%

\(\rightarrow\)%mCu=6,67%

b. \(\text{mCu=12-0,2.56=0,8}\)

Khối lượng ddB: \(\text{m=12+200-mH2-mCu=210,8}\)

a) Fe+H2SO4--->FeSO4+H2

Chất rắn A là Cu, B là FeSO4

n H2=04/2=0,2(mol)

Theo pthh

n Fe=n H2=0,2(mol)

m Fe=56/0,2=11,2(g)

m Cu=12-11,2=0,8(g)

b) m dd B =m Fe+m dd H2SO4-m H2

=11,2+200-0,4=210,8(g)

PTHH Fe+H2SO4\(\rightarrow\)FeSO4+H2

Cu ( không pư với H2SO4 loãng)

Số mol H2 là:

nH2=\(\frac{0,4}{2}\)= 0,2mol

Số mol Fe là\(\frac{0,2.1}{1}\)= 0,2mol

Khối lượng Fe là

m= 0,2.56= 11,2g

Khối lượng Cu là

12-11,2= 0,8g

Ta có mFe+ mddH2SO4= mddFeSO4+ mH2

\(\rightarrow\) mdd FeSO4= mFe+mddH2SO4-mH2

= 11,2+200- 0,4=210,8g

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

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

    0,1                    0,1         0,1

   \(m_{Fe}=0,1\cdot56=5,6\left(g\right)\)

b)\(\Rightarrow\%m_{Fe}=\dfrac{5,6}{12}\cdot100\%=46,67\%\)   \(\Rightarrow\%m_{Cu}=100\%-46,67\%=53,33\%\)

c)\(n_{NaOH}=0,1\cdot1=0,1mol\)

   \(2NaOH+FeCl_2\rightarrow Fe\left(OH\right)_2+2NaCl\)

    0,1             0,1            0,1

   \(m_{Fe\left(OH\right)_2}=0,1\cdot90=9\left(g\right)\)

\(n_{H_2}=\dfrac{3,36}{22,4}0,15(mol)\\ a,PTHH:Fe+H_2SO_4\to FeSO_4+H_2\\ b,n_{Fe}=n_{H_2}=0,15(mol)\\ \Rightarrow \%_{Fe}=\dfrac{0,15.56}{14,8}.100\%=56,76\%\\ \Rightarrow \%_{Cu}=100\%-56,76\%=43,24\%\\ c,n_{H_2SO_4}=0,15(mol)\\ \Rightarrow m_{dd_{H_2SO_4}}=\dfrac{0,15.98}{20\%}=73,5(g)\\ \Rightarrow V_{dd_{H_2SO_4}}=\dfrac{73,5}{1,4}=52,5(l)\)

a) \(n_{H_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

PTHH: Fe + H₂SO₄ --> FeSO₄ + H₂

_____0,3<---0,3<------------------0,3

=> m_Fe = 0,3.56 = 16,8(g)

=> m_{rắn còn lại} = m_Cu = 29,6-16,8 = 12,8 (g)

b) \(V_{ddH_2SO_4}=\dfrac{0,3}{1}=0,3\left(l\right)\)

PTHH: \(Fe+H_2SO_4\rightarrow FeSO_4+H_2\uparrow\)

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

\(\Rightarrow m_{Fe}=0,25\cdot56=14\left(g\right)\) \(\Rightarrow m_{Cu}=6\left(g\right)\)

b) Theo PTHH: \(n_{FeSO_4}=0,25mol\) \(\Rightarrow m_{FeSO_4}=0,25\cdot152=38\left(g\right)\)

Mặt khác: \(\left\{{}\begin{matrix}m_{ddH_2SO_4}=\dfrac{0,25\cdot98}{10\%}=245\left(g\right)\\m_{H_2}=0,25\cdot2=0,5\left(g\right)\end{matrix}\right.\)

\(\Rightarrow m_{dd}=m_{hh}+m_{H_2SO_4}-m_{Cu}-m_{H_2}=258,5\left(g\right)\)

\(\Rightarrow C\%_{FeSO_4}=\dfrac{38}{258,5}\cdot100\%\approx14,7\%\)

pthh : Fe +H₂SO₄ → FeSO₄ +H₂

theo bài ra số mol của h2 =0,15 (mol)

theo pt : nFe=nH₂=0,15 (mol)

mFe=0,15 .56 =8,4 (g) ⇒mCu=20-8,4=11,6 (g)

a/nH2= 0,1(mol)

Fe + H2SO4 -> FeSO4 + H2

0,1_________________0,1(mol)

=> mFe=0,1.56=5,6(g)

=> %mFe= (5,6/12).100\(\approx\) 46,667%

=> %mCu \(\approx\) 100% - 46,667% \(\approx\) 53,333%

b) mCu= 12-5,6=6,4(g) -> nCu= 0,1(mol)

Cu + 2 H2SO4(đ) -to-> CuSO4 + SO2 + 2 H2O

0,1___0,2__________________0,1(mol)

V=V(SO2,đktc)=0,1.22,4=2,24(l)

mH2SO4(p.ứ)=0,2.98=19,6(g)

=> mH2SO4(bđ)= 19,6 x 100/90 \(\approx21,778\left(g\right)\)

=> mddH2SO4 \(\approx\) (21,778 x 100)/98\(\approx22,222\left(g\right)\)

Vì Cu không tác dụng với HCl 

\(n_{H2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

Pt : \(Fe+2HCl\rightarrow FeCl_2+H_2|\)

       1         2              1           1

      0,1     0,2                           0,1

a) \(n_{Fe}=\dfrac{0,1.1}{1}=0,1\left(mol\right)\)

\(m_{Fe}=0,1.56=5,6\left(g\right)\)

\(m_{Cu}=12-5,6=6,4\left(g\right)\)

b) \(n_{HCl}=\dfrac{0,1.2}{1}=0,2\left(mol\right)\)

200ml = 0,2l

\(C_{M_{ddHCl}}=\dfrac{0,2}{0,2}=1\left(M\right)\)

c) ⁰/₀Fe = \(\dfrac{5,6.100}{12}=46,67\)⁰/₀

    ⁰/₀Cu = \(\dfrac{6,4.100}{12}=53,33\)⁰/₀

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