\(a,n_{\left(CH_3COO\right)_2Mg}=\dfrac{7,1}{142}=0,05\left(mol\right)\)

PTHH: \(Mg+2CH_3COOH\rightarrow\left(CH_3COO\right)_2Mg+H_2\uparrow\)

                        0,1<----------------0,05-------------->0,05

\(\rightarrow V_{H_2}=0,05.22,4=1,12\left(l\right)\\ b,C\%_{CH_3COOH}=\dfrac{0,1.60}{100}.100\%=6\%\)

\(c,n_{C_2H_5OH}=\dfrac{6,9}{46}=0,15\left(mol\right)\)

PTHH: \(CH_3COOH+C_2H_5OH\xrightarrow[H_2SO_{4\left(đặc\right)}]{t^o}CH_3COOC_2H_5+H_2O\)

bđ          0,1                 0,15

pư          0,1                 0,1

spư         0                     0,05                          0,1

\(\rightarrow m_{este}=0,1.80\%.88=7,04\left(g\right)\)

a) Gọi \(\left\{{}\begin{matrix}n_{Zn}=a\left(mol\right)\\n_{Al}=b\left(mol\right)\end{matrix}\right.\left(\text{Đ}K:a,b>0\right)\)

PTHH: Zn + H₂SO₄ ---> ZnSO₄ + H₂ 

           a------>a---------->a----------->a

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

           b----->1,5b--------->0,5b------->1,5a

=> \(\left\{{}\begin{matrix}65a+27b=20,3\\161b+0,5a.342=65,9\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0,25\\b=0,15\end{matrix}\right.\)

=> \(V=V_{H_2}=\left(0,25+0,15.1,5\right).22,4=10,64\left(l\right)\)

b) \(\left\{{}\begin{matrix}\%m_{Zn}=\dfrac{0,25.65}{20,3}.100\%=80,05\%\\\%m_{Al}=100\%-80,05\%=19,95\%\end{matrix}\right.\)

c) \(m_{\text{dd}H_2SO_4}=\dfrac{\left(0,25+1,5.0,15\right).98}{10\%}=465,5\left(g\right)\)

Bảo toàn nguyên tố ta có

\(n_{H_2}=n_{H_2SO_4}=\dfrac{6,72}{22,4}=0.3\) (mol)

Sau khi cô cạn dd ta được : ion kim loại : 11,3g và SO₄^2- 0.3 mol

⇒ m = 30.5 g

\(n_{Zn}=\dfrac{8,125}{65}=0,125\left(mol\right)\\ m_{HCl}=\dfrac{100.18,25}{100}=18,25\left(g\right)\\ n_{HCl}=\dfrac{18,25}{36,5}=0,5\\ pthh:Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)  
            0,125                            0,125 (mol ) 
\(\Rightarrow V_{H_2}=0,125.22,4=2,8\left(l\right)\\ \)   
\(C\%=\dfrac{8,125}{8,125+18,25}.100\%=30,8\%\)
 

Bài 18:

Ta có: \(n_{Zn}=\dfrac{8,125}{65}=0,125\left(mol\right)\)

\(m_{HCl}=100.18,25\%=18,25\left(g\right)\Rightarrow n_{HCl}=\dfrac{18,25}{36,5}=0,5\left(mol\right)\)

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

b, Xét tỉ lệ: \(\dfrac{0,125}{1}< \dfrac{0,5}{2}\), ta được HCl dư.

Theo PT: \(n_{H_2}=n_{Zn}=0,125\left(mol\right)\)

\(\Rightarrow V_{H_2}=0,125.22,4=2,8\left(g\right)\)

\(m_{H_2}=0,125.2=0,25\left(g\right)\)

c, Theo PT: \(\left\{{}\begin{matrix}n_{ZnCl_2}=n_{Zn}=0,125\left(mol\right)\\n_{HCl\left(pư\right)}=2n_{Zn}=0,25\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow n_{HCl\left(dư\right)}=0,25\left(mol\right)\)

Có: m _{dd sau pư} = 8,125 + 100 - 0,25 = 107,875 (g)

\(\Rightarrow\left\{{}\begin{matrix}C\%_{ZnCl_2}=\dfrac{0,125.136}{107,875}.100\%\approx15,76\%\\C\%_{HCl\left(dư\right)}=\dfrac{0,25.36,5}{107,875}.100\%\approx8,46\%\end{matrix}\right.\)

Bạn tham khảo nhé!

`a)PTHH:`

`Zn + 2HCl -> ZnCl_2 + H_2↑`

`0,125`  `0,25`    `0,125`    `0,125`      `(mol)`

`b)n_[Zn] = [ 8,125 ] / 65 = 0,125 (mol)`

`n_[HCl] = [ [ 18,25 ] / 100 . 100 ] / [ 36,5 ] = 0,5 (mol)`

Ta có: `[ 0,125 ] / 1 < [ 0,5 ] / 2`

    `-> Zn` hết, `HCl` dư

 `=> V_[H_2] = 0,125 . 22,4 = 2,8 (l)`

 `=> m_[H_2] = 0,125 . 2 = 0,25 (g)`

`c)m_\text{dd sau p/ứ} = 8,125 + 100 - 0,25 = 107,875 (g)`

`=> C%_[ZnCl_2] = [ 0,125 . 136 ] / [ 107,875 ] . 100 ~~ 15,76%`

`=> C%_[HCl(dư)] = [ ( 0,5 - 0,25 ) . 36,5 ] / [ 107,875 ] . 100 ~~ 8,46%`

Ta có : \(n_{HNO_3}=4n_{NO}=0,18\left(mol\right)\)

=> \(n_{NO}=0,045\left(mol\right)\Rightarrow V_{NO}=1,008\left(l\right)\)

\(n_{NO_3^-\left(taomuoi\right)}=3n_{NO}=0,135\left(mol\right)\)

\(m_{muối}=m_{Zn}+m_{NO_3^-\left(taomuoi\right)}+m_{SO_4^{2-}}=32,52\left(g\right)\)