a, PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)

b, Ta có: \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)

Theo PT: \(n_{H_2}=n_{Zn}=0,1\left(mol\right)\Rightarrow V_{H_2}=0,1.22,4=2,24\left(l\right)\)

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

Theo PT: \(n_{Fe}=\dfrac{2}{3}n_{H_2}=\dfrac{1}{15}\left(mol\right)\Rightarrow m_{Fe}=\dfrac{1}{15}.56=\dfrac{56}{15}\left(g\right)\)

a. \(PTHH:Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\)

\(n_{Mg}=\dfrac{m_{Mg}}{M_{Mg}}=\dfrac{12}{24}=0,5\left(mol\right)\)

- Mol theo PTHH : \(1:2:1:1\)

- Mol theo phản ứng : \(0,5\rightarrow1\rightarrow0,5\rightarrow0,5\)

\(\Rightarrow n_{H_2}=0,5\left(mol\right)\)

\(\Rightarrow V_{H_2}=n_{H_2}.22,4=0,5.22,4=11,2\left(l\right)\)

b. Từ a. \(\Rightarrow n_{HCl}=1\left(mol\right)\)

\(\Rightarrow m_{HCl}=n_{HCl}.M_{HCl}=1.\left(1+35,5\right)=36,5\left(g\right)\)

c. \(n_{O_2}=\dfrac{V_{O_2}}{22,4}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

\(PTHH:2H_2+O_2\underrightarrow{t^o}2H_2O\)

- Mol theo PTHH : \(2:1:2\)

- Mol theo phản ứng : \(0,6\leftarrow0,3\rightarrow0,6\)

\(\Rightarrow n_{H_2O}=0,6\left(mol\right)\)

\(\Rightarrow m_{H_2O}=n_{H_2O}.M_{H_2O}=0,6.\left(2+16\right)=10,8\left(g\right)\)

a)

Zn+2HCl->ZnCl2+H2

0,1-----------------0,1

n Zn=0,1 mol

3H2+Fe2O3-to>2Fe+3h2O

0,2---0,067

=>m Fe2O3=0,067.160=10,72g

=>VH2=0,1.22,4=2,24l

a)

\(n_{Fe}=\dfrac{11,2}{56}=0,2\left(mol\right)\)

PTHH: Fe + H₂SO₄ --> FeSO₄ + H₂

            0,2----------------------->0,2

=> V_H2 = 0,2.22,4 = 4,48 (l)

b) 

PTHH: 2H₂ + O₂ --t^o--> 2H₂O

             0,2-->0,1

PTHH: 2KMnO₄ --t^o--> K₂MnO₄+ MnO₂ + O₂

                  0,2<------------------------------0,1

=> \(m_{KMnO_4}=0,2.158=31,6\left(g\right)\)

c) \(n_{O_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

PTHH: 3Fe + 2O₂ --t^o--> Fe₃O₄

Xét tỉ lệ: \(\dfrac{0,2}{3}>\dfrac{0,1}{2}\) => Fe dư

a.\(n_{Fe}=\dfrac{11,2}{56}=0,2\left(mol\right)\)

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

0,2                                      0,2   ( mol )

\(V_{H_2}=0,2.22,4=4,48\left(l\right)\)

b.\(2H_2+O_2\rightarrow\left(t^o\right)2H_2O\)

  0,2       0,1                       ( mol )

\(2KMnO_4\rightarrow\left(t^o\right)K_2MnO_4+MnO_2+O_2\uparrow\)

     0,2                                                        0,1  ( mol )

\(m_{KMnO_4}=0,2.158=31,6\left(g\right)\)

c.\(n_{O_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

      \(3Fe+2O_2\rightarrow\left(t^o\right)Fe_3O_4\)

Xét: \(\dfrac{0,2}{3}\) > \(\dfrac{0,1}{2}\)                        ( mol )

--> Sắt không cháy hết

\(n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\)

PTHH: Fe + 2HCl --> FeCl₂ + H₂

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

=> V_H2 =0,1.22,4 = 2,24(l)

\(PTHH:Fe+2HCl\rightarrow FeCl_2+H_2\\ n_{Fe}=\dfrac{m}{M}=\dfrac{5,6}{56}=0,1\left(mol\right)\\ Theo.PTHH:n_{H_2}=n_{Fe}=0,1\left(mol\right)\\ V_{H_2\left(đktc\right)}=n.22,4=0,1.22,4=2,24\left(l\right)\)

1)

a) Fe + 2HCl --> FeCl₂ + H₂

b) \(n_{Fe}=\dfrac{8,4}{56}=0,15\left(mol\right)\)

PTHH: Fe + 2HCl --> FeCl₂ + H₂

           0,15->0,3--->0,15-->0,15

=> V_H2 = 0,15.22,4 = 3,36 (l)

c) m_{dd sau pư} = 8,4 + 250 - 0,15.2 = 258,1 (g)

=> \(C\%_{FeCl_2}=\dfrac{0,15.127}{258,1}.100\%=7,38\%\)

2)

a) Zn + 2HCl --> ZnCl₂ + H₂

b) \(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)

PTHH: Zn + 2HCl --> ZnCl₂ + H₂

            0,2-->0,4---->0,2--->0,2

=> V_H2 = 0,2.22,4 = 4,48 (l)

m_ZnCl2 = 0,2.136 = 27,2 (g)

c) \(C_{M\left(dd.HCl\right)}=\dfrac{0,4}{0,2}=2M\)

d) 

PTHH: A + 2HCl --> ACl₂ + H₂

           0,2<--0,4

=> \(M_A=\dfrac{4,8}{0,2}=24\left(g/mol\right)\)

=> A là Mg(Magie)

Theo gt ta có: $n_{Zn}=0,1(mol)$

a, $Zn+2HCl\rightarrow ZnCl_2+H_2$

b, Ta có: $n_{H_2}=0,1(mol)\Rightarrow V_{H_2}=2.24(l)$

c, Ta có: $n_{HCl}=2.n_{Zn}=0,2(mol)\Rightarrow m_{HCl}=7,3(g)$

\(a)\\ Zn + 2HCl \to ZnCl_2 + H_2\\ b)\\ n_{H_2} = n_{Zn} = \dfrac{6,5}{65} = 0,1(mol)\\ \Rightarrow V_{H_2} = 0,1.22,4 = 2,24(lít)\\ c)\\ n_{HCl} = 2n_{Zn} = 0,1.2 = 0,2(mol)\\ \Rightarrow m_{HCl} = 0,2.36,5 = 7,3\ gam\)

a. \(Fe+2HCl\rightarrow FeCl_2+H_2\)

b. \(n_{Fe}=\dfrac{m_{Fe}}{M_{Fe}}=\dfrac{28}{56}=0,5\left(mol\right)\)

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

0,5-------1---------0,5-----0,5

Theo PTHH: \(\Rightarrow n_{H_2}=n_{Fe}=0,5\left(mol\right)\)

\(V_{H_2}=n_{H_2}.22,4=0,5.22,4=11,2\left(l\right)\)

c. \(H_2+CuO\rightarrow Cu+H_2O\)

  0,5-------0,5-----0,5----0,5

\(\Rightarrow m_{Cu}=n_{Cu}.M_{Cu}=0,5.64=32\left(g\right)\)