a, nH2=5,6/22,4=0,25 mol

Zn+2HCl->ZnCl2+H2

0,25  0,5      0,25     0,25

mZn pư=0,25.65=16,25 g

b, C%HCl=0,5.36,5.100/200=9,125%

Gọi x, y lần lượt là số mol của Zn và Fe

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

a. PTHH:

Zn + 2HCl ---> ZnCl₂ + H₂ (1)

Fe + 2HCl ---> FeCl₂ + H₂ (2)

Theo PT₍₁₎: \(n_{H_2}=n_{Zn}=x\left(mol\right)\)

Theo PT₍₂₎: \(n_{H_2}=n_{Fe}=y\left(mol\right)\)

=> x + y = 0,3 (*)

Theo đề, ta có: 65x + 56y = 17,7 (**)

Từ (*) và (**), ta có HPT:

\(\left\{{}\begin{matrix}x+y=0,3\\65x+56y=17,7\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0,1\\y=0,2\end{matrix}\right.\)

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

=> \(\%_{m_{Zn}}=\dfrac{6,5}{17,7}.100\%=36,72\%\)

\(\%_{m_{Fe}}=100\%-36,72\%=63,28\%\)

b. Ta có: \(n_{hh_{Zn,Fe}}=0,1+0,2=0,3\left(mol\right)\)

Theo PT_{(1, 2)}: \(n_{HCl}=2.n_{hh}=2.0,3=0,6\left(mol\right)\)

=> \(m_{HCl}=0,6.36,5=21,9\left(g\right)\)

=> \(C_{\%_{HCl}}=\dfrac{21,9}{200}.100\%=10,95\%\)

a, \(Zn+2HCl\rightarrow ZnCl_2+H_2\)

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

Theo PT: \(n_{Zn}=n_{H_2}=0,3\left(mol\right)\)

\(\Rightarrow m_{Zn}=0,3.65=19,5\left(g\right)\)

c, \(n_{HCl}=2n_{H_2}=0,6\left(mol\right)\)

\(\Rightarrow C_{M_{HCl}}=\dfrac{0,6}{0,1}=6\left(M\right)\)

\(n_{H_2}=\dfrac{1,12}{22,4}=0,05\left(mol\right)\\ a.Zn+2HCl\rightarrow ZnCl_2+H_2\\ 0,05.........0,1..........0,05..........0,05\left(mol\right)\\ a.C\%_{ddHCl}=\dfrac{0,1.36,5}{200}.100=1,825\%\\ b.m_{Zn}=0,05.65=3,25\left(g\right)\\ c.C\%_{ddZnCl_2}=\dfrac{136.0,05}{3,25+200-0,05.2}.100\approx3,347\%\)

\(n_{H_2}=\dfrac{7,84}{22,4}=0,35\left(mol\right)\)

PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)

____0,35_____0,7___________0,35 (mol)

a, \(m_{Zn}=0,35.65=22,75\left(g\right)\)

b, \(C\%_{HCl}=\dfrac{0,7.36,5}{200}.100\%=12,775\%\)

\(a)n_{H_2}=\dfrac{7,84}{22,4}=0,35mol\\ Zn+2HCl\rightarrow ZnCl_2+H_2\)

0,35        0,7            0,35         0,35

\(m_{Zn}=0,35.65=22,75g\\ b)C_{\%HCl}=\dfrac{0,7.36,5}{200}\cdot100\%=12,775\%\)

a,\(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)

PTHH: Zn + 2HCl → ZnCl₂ + H₂

Mol:    0,1      0,2        0,1          0,1

b,\(V_{H_2}=0,1.24,79=2,479\left(l\right)\)

c,\(m_{ddHCl}=\dfrac{0,2.36,5.100}{3,65}=200\left(g\right)\)

d,\(m_{ZnCl_2}=0,1.136=13,6\left(g\right)\)

e,m_{dd sau pứ} = 6,5+200-0,1.2 = 206,3 (g)

\(C\%_{ddZnCl_2}=\dfrac{13,6.100\%}{206,3}=6,59\%\)

giúp

Bài 3 : 

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

a) Pt : \(Zn+2HCl\rightarrow ZnCl_2+H_2|\)

            1          2             1           1

           0,1      0,2           0,1        0,1

b) \(n_{H2}=\dfrac{0,1.1}{1}=0,1\left(mol\right)\)

\(V_{H2\left(dktc\right)}=0,1.22,4=2,24\left(l\right)\)

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

\(m_{HCl}=0,2.36,5=7,3\left(g\right)\)

\(m_{ddHCl}=\dfrac{7,3.100}{3,65}=200\left(g\right)\)

d) \(n_{ZnCl2}=\dfrac{0,1.1}{1}=0,1\left(mol\right)\)

⇒ \(m_{ZnCl2}=0,1.136=13,6\left(g\right)\)

e) \(m_{ddspu}=6,5+200-\left(0,1.2\right)=206,3\left(g\right)\)

\(C_{ZnCl2}=\dfrac{13,6.100}{206,3}=6,6\)⁰/₀

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