\(Al+3HCl\rightarrow AlCl_3+\frac{3}{2}H_2\)

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

BTKL: m dung dịch trước phản ứng + m kim loại = m dung dịch sau phản ứng + mH2

\(m_{tang}=m_{kl}-m_{H2}\)

\(\Rightarrow m_{H2}=11-10,2=0,8\left(g\right)\Rightarrow n_{H2}=\frac{0,8}{2}=0,4\left(mol\right)\)

Gọi số mol Al và Fe lần lượt là x, y

\(\left\{{}\begin{matrix}27x+56y=11\\1,5x+y=0,4\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,2\\y=0,4\end{matrix}\right.\)

Tự tính % nha

a) Gọi số mol Al, Fe là a, b (mol)

=> 27a + 56b = 13,9 (1)

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

PTHH: 2Al + 6HCl --> 2AlCl₃ + 3H₂

             a--->3a--------------->1,5a

             Fe + 2HCl --> FeCl₂ + H₂

             b-->2b---------------->b

=> 1,5a + b = 0,35 (2)

(1)(2) => a = 0,1; b = 0,2

n_HCl = 3a + 2b = 0,7 (mol)

=> m_HCl = 0,7.36,5 = 25,55(g)

b) 

m_Al = 0,1.27 = 2,7 (g)

m_Fe = 0,2.56 = 11,2 (g)

a, \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

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

b, Ta có: m _{dd tăng} = m_KL - m_H2

⇒ m_H2 = 16,6 - 15,6 = 1 (g) \(\Rightarrow n_{H_2}=\dfrac{1}{2}=0,5\left(mol\right)\)

Có: 27n_Al + 56n_Fe = 16,6 (1)

Theo PT: \(n_{H_2}=\dfrac{3}{2}n_{Al}+n_{Fe}=0,5\left(2\right)\)

Từ (1) và (2) ⇒ n_Al = n_Fe = 0,2 (mol)

\(\Rightarrow\left\{{}\begin{matrix}m_{Al}=0,2.27=5,4\left(g\right)\\m_{Fe}=0,2.56=11,2\left(g\right)\end{matrix}\right.\)

c, Theo PT: \(n_{HCl}=2n_{H_2}=1\left(mol\right)\Rightarrow m_{ddHCl}=\dfrac{1.36,5}{40\%}=91,25\left(g\right)\)

⇒ m _{dd sau pư} = 91,25 + 15,6 = 106,85 (g)

Theo PT: \(\left\{{}\begin{matrix}n_{AlCl_3}=n_{Al}=0,2\left(mol\right)\\n_{FeCl_2}=n_{Fe}=0,2\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}C\%_{AlCl_3}=\dfrac{0,2.133,5}{106,85}.100\%\approx24,98\%\\C\%_{FeCl_2}=\dfrac{0,2.127}{106,85}.100\%\approx23,77\%\end{matrix}\right.\)

\(2Al+6HCl->2AlCl_3+3H_2\\ Fe+2HCl->FeCl_2+H_2\\ n_{H_2}=\dfrac{16,6-15,6}{2}=0,5mol\\ n_{HCl}=1mol\\ n_{Al}=a;n_{Fe}=b\\ 27a+56b=16,6\\ 3a+2b=1\\ a=b=0,2\\ m_{Al}=0,2.27=5,4g\\ m_{Fe}=0,2.56=11,2g\\ m_{ddsau}=15,6+\dfrac{36,5}{0,4}=106,85g\\ C\%_{AlCl_3}=\dfrac{133,5.0,2}{106,85}.100\%=24,99\%\\ C\%_{FeCl_2}=\dfrac{127.0,2}{106,85}.100\%=23,77\%\)

\(n_{H_2} = \dfrac{4,35-3,95}{2} = 0,2(mol)\\ Mg + 2HCl \to MgCl_2 + H_2\\ 2Al + 6HCl \to 2AlCl_3 + 3H_2\)

\(\left\{{}\begin{matrix}Mg:x\left(mol\right)\\Al:y\left(mol\right)\end{matrix}\right.\)→ \(\left\{{}\begin{matrix}24x+27y=4,35\\x+1,5y=0,2\end{matrix}\right.\)→\(\left\{{}\begin{matrix}x=0,125\\y=0,05\end{matrix}\right.\)

Vậy :

\(\%m_{Mg} = \dfrac{0,125.24}{4,35}.100\% = 68,97\%\\ \%m_{Al} = 100\% - 68,97\% = 31,03\%\)

.

\(n_{H_2} = \dfrac{15,6-14}{2} = 0,8(mol)\\ 2Al + 6HCl \to 2AlCl_3 + 3H_2\\ Mg + 2HCl \to MgCl_2 + H_2\)

Gọi \(n_{Al} = a \ mol;n_{Mg} = b\ mol\)

Ta có :

\(\left\{{}\begin{matrix}27a+24b=15,6\\1,5a+b=0,8\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}a=0,4\\b=0,2\end{matrix}\right.\)

Vậy : 

\(\%m_{Al} = \dfrac{0,4.27}{15,6}.100\% = 69,23\%\\ \%m_{Mg} = 100\% - 69,23\% = 30,77\%\)

Khối lượng dung dịch tăng = m hỗn hợp kim loại - m khí H2 thoát ra

\(\Rightarrow\Delta m=m_{hh\left(kl\right)}-m_{H2}\)

\(\Rightarrow10,2=m_{hh\left(kl\right)}-m_{H2}\rightarrow m_{hh\left(kl\right)}=10,2+m_{H2}\)

Bảo toàn mol H \(\Rightarrow n_{HCl}=2n_{H2}\)

Áp dụng BTKL:

\(m_{hh\left(kl\right)}+36,5.n_{HCl}=39,4+2.n_{H2}\)

\(\Rightarrow10,2+m_{H2}+36,5.2.n_{H2}=39,4+2.n_{H2}\)

\(\Rightarrow10,2+2.n_{H2}+36,5.2.n_{H2}=39,4+2.n_{H2}\)

\(\Rightarrow n_{H2}=0,4\left(mol\right)\)

\(\Rightarrow m_{H2}=0,4.2=0,8\left(mol\right)\)

\(m_{hh\left(kl\right)}=10,2+0,8=11\left(g\right)\)

Gọi số mol Al, Fe lần lượt là

Ta có HPT:

\(\left\{{}\begin{matrix}27x+56y=11\\1,5x+y=0,4\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,2\left(mol\right)\\y=0,1\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow m_{Al}=0,2.27=5,4\left(g\right)\)

\(\Rightarrow\%m_{Al}=\frac{5,4}{11}.100\%=49,1\%\)

\(\Rightarrow\%m_{Fe}=100\%-49,1\%=50,9\%\)

\(a,Mg+H_2SO_4\rightarrow MgSO_4+H_2\\ 2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\\ m_{tăng}=m_{hhMg,Al}-m_{H_2}\\ \Leftrightarrow7=7,8-m_{H_2}\\ \Leftrightarrow m_{H_2}=0,8\left(g\right)\\ \Rightarrow n_{H_2}=\dfrac{0,8}{2}=0,4\left(mol\right)\\ Đặt:a=n_{Al}\left(mol\right);n_{Mg}=b\left(mol\right)\left(a,b>0\right)\\ \Rightarrow\left\{{}\begin{matrix}24b+27a=7,8\\b+1,5a=0,4\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0,2\\b=0,1\end{matrix}\right.\\m_{Mg}=24.0,1=2,4\left(g\right);m_{Al}=0,2.27=5,4\left(g\right)\\ \Rightarrow\%m_{Al}=\dfrac{0,2.27}{7,8}.100\approx69,231\%\\ \Rightarrow\%m_{Mg}\approx30,769\%\\ c,m_{muối}=m_{MgSO_4}+m_{Al_2\left(SO_4\right)_3}=120b+342.0,5a=120.0,1+342.0,5.0,2=46,2\left(g\right)\)

giúp em với ạ

2Al+6Hcl->2AlCl₃+3H₂

x-----------------x--------3\2x

Fe+2HCl->FeCl₂+H₂

y-----------------y------y 

Ta có :

\(\left\{{}\begin{matrix}27x+56y=9,65\\\dfrac{3}{2}x+y=0,325\end{matrix}\right.\)

=>x=0,15 mol, y=0,1 mol

=>m Al=0,15.27=4,05g

=>m Fe=56.0,1=5,6g

b)

=>m AlCl3=0,15.133,5=20,025g

=>m FeCl2=0,1.127=12,7g

\(\left\{{}\begin{matrix}Al\\Fe\end{matrix}\right.+HCl->\left\{{}\begin{matrix}AlCl3\\FeCl2\end{matrix}\right.+7,28lH2\)

a, 

Ta có :

\(\left\{{}\begin{matrix}27x+56y=9,65\\3x+2y=0,65\left(bt-e\right)\end{matrix}\right.\)

\(\left\{{}\begin{matrix}x=0,15\left(mol\right)\\y=0,1\left(mol\right)\end{matrix}\right.\)

\(\left\{{}\begin{matrix}mAl=0,15.27=4,05\left(g\right)\\mFe=0,1.56=5,6\left(g\right)\end{matrix}\right.\)

b,

Bảo toàn nguyên tố :

nAl = nAlCl3 = 0,15 ( mol )

nFe = nFeCl2 = 0,1 ( mol )

Khối lượng chất tan A :

m = 0,15 . 133,5 + 0,1 . 127 = 32,725(g)

a/ Fe + 2HCl \(\rightarrow\) FeCl₂ + H₂

n_H2 = \(\dfrac{3,36}{22,4}=0,15\left(mol\right)\)

Theo PTHH: n_H2 = n_Fe = 0,15 (mol) \(\Rightarrow m_{Fe}=0,15.56=8,4\left(g\right)\)

\(\Rightarrow m_{Cu}=11-8,4=2,6\left(g\right)\)

\(\Rightarrow\%m_{Fe}=\dfrac{8,4}{11}.100\%\approx76,4\%\)

\(\Rightarrow\%m_{Cu}=100-76,4\approx23,6\%\)

b/ Theo PTHH ta có: n_HCl = 2n_Fe = 2.0,15 = 0,3 (mol)

\(\Rightarrow V_{ddHCl}=\dfrac{0,3}{2}=0,15\left(M\right)\)

c/ m_HCl = 36,5 . 0,3 = 10,95(g)

\(\Rightarrow C\%_{HCl}=\dfrac{m_{HCl}}{m_{ddHCl}}.100\%=\dfrac{10,95}{200}.100\%=5,475\%\)