\(n_{Fe}=\dfrac{11,2}{56}=0,2\left(mol\right)\\a, PTHH:Fe+H_2SO_4\rightarrow FeSO_4+H_2\\ b,n_{H_2}=n_{H_2SO_4}=n_{Fe}=0,2\left(mol\right)\\ V_{H_2\left(đkc\right)}=0,2.24,79=4,958\left(l\right)\\ c,C_{MddH_2SO_4}=\dfrac{0,2}{0,4}=0,5\left(M\right)\)

`a)PTHH:`

`2Al + 6HCl -> 2AlCl_3 + 3H_2`

`0,2`     `0,6`                               `0,3`       `(mol)`

`n_[Al]=[5,4]/27=0,2(mol)`

`b)V_[H_2]=0,3.22,4=6,72(l)`

`c)m_[dd HCl]=[0,6.36,5]/10 . 100 =219(g)`

n_Al  = \(\dfrac{5,4}{27}\) = 0,2 (mol)

 2Al + 6HCl -> 2AlCl₃ + 3H₂

     0,2     0,6       0,2      0,3

=>VH2=0,3.22,4=6,72l

=>mHcl=0,6.36,5=21,9g

=>mdd=219g

\(a.Mg+2HCl\rightarrow MgCl_2+H_2\\ 2Al+6HCl\rightarrow2AlCl_3+3H_2\\ b.Đặt:\left\{{}\begin{matrix}n_{Mg}=x\left(mol\right)\\n_{Al}=y\left(mol\right)\end{matrix}\right.\\ n_{H_2}=\dfrac{18,48}{22,4}=0,825\left(mol\right)\\ Tacó:\left\{{}\begin{matrix}24x+27y=17,1\\x+\dfrac{3}{2}y=0.825\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}x=0,375\\y=0,3\end{matrix}\right.\\ \Rightarrow\%m_{Mg}=\dfrac{0,375.24}{17,1}.100=52,63\%\\ \%m_{Al}=47,37\%\)

a)

$Fe + 2HCl \to FeCl_2 + H_2$
n H2 = n Fe = 11,2/56 = 0,2(mol)

V H2 = 0,2.22,4 = 4,48(lít)

b)

n HCl = 2n Fe = 0,2.2 = 0,4(mol)

=> CM HCl = 0,4/0,4 = 1M

c)

$CuO + H_2 \xrightarrow{t^o} Cu + H_2O$

Ta thấy :

n CuO = 64/80 = 0,8 > n H2 = 0,2 nên CuO dư

Theo PTHH :

n CuO pư = n Cu = n H2 = 0,2(mol)

n Cu dư = 0,8 - 0,2 = 0,6(mol)

Vậy : 

%m Cu = 0,2.64/(0,2.64 + 0,6.80)   .100% = 21,05%
%m CuO = 100% -21,05% = 78,95%

\(n_{Al\left(OH\right)_3}=\dfrac{7,8}{78}=0,1mol\\ 2Al\left(OH\right)_3+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+6H_2O\\ 0,1................0,15.............0,05............0,3\\ C_{\%H_2SO_4}=\dfrac{0,15.98}{300}\cdot100\%=4,9\%\\ C_{\%Al_2\left(SO_4\right)_3}=\dfrac{0,05.342}{7,8+300}\cdot100\%=5,56\%\)

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)

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

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

_____0,2____0,4_____0,2___0,2 (mol)

b, Ta có: m _{dd sau pư} = m_Zn + m _{dd HCl} - m_H2 = 13 + 100 - 0,2.2 = 112,6 (g)

\(\Rightarrow C\%_{ZnCl_2}=\dfrac{0,2.136}{112,6}.100\%\approx24,16\%\)

c, Ta có: m_HCl = 0,4.36,5 = 14,6 (g)

\(\Rightarrow C\%_{HCl}=\dfrac{14,6}{100}.100\%=14,6\%\)

Bạn tham khảo nhé!

a, PTHH:   Zn  +  2HCl  ➝  ZnCl₂  +  H₂

    (mol)       1           2              1          1

    (mol)      0.2

b, n_Zn=13 :65 =0.2 (mol)

Theo PTHH: n_ZnCl2=(0.2x1):1=0.2(mol)

→m_ZnCl2=0.2x(65+2x35.5)=27.2(g)

⇒C%_ZnCl2=27.2:100x100=27.2(%)

c,Theo PTHH: n_HCl =(0.2 x 2) :1=0.4(mol)

➝m_HCl=0.4x(1+35.5)=14.6(g)

⇒C%_HCl=14.6:100x100%=14.6(%)