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

Ta có: \(\left\{{}\begin{matrix}n_{Mg}=\dfrac{2,4}{24}=0,1\left(mol\right)\\n_{HCl}=\dfrac{109,5\cdot10\%}{36,5}=0,3\left(mol\right)\end{matrix}\right.\)

Xét tỉ lệ: \(\dfrac{0,1}{1}< \dfrac{0,3}{2}\) \(\Rightarrow\) HCl còn dư, Magie p/ứ hết

\(\Rightarrow n_{Mg}=n_{MgCl_2}=n_{H_2}=0,1\left(mol\right)=n_{HCl\left(dư\right)}\)

\(\Rightarrow\left\{{}\begin{matrix}m_{MgCl_2}=0,1\cdot95=9,5\left(g\right)\\m_{HCl\left(dư\right)}=0,1\cdot36,5=3,65\left(g\right)\\m_{H_2}=0,1\cdot2=0,2\left(g\right)\end{matrix}\right.\)

Mặt khác: \(m_{dd\left(saup/ứ\right)}=m_{Mg}+m_{ddHCl}-m_{H_2}=111,7\left(g\right)\)

\(\Rightarrow\left\{{}\begin{matrix}C\%_{MgCl_2}=\dfrac{9,5}{111,7}\cdot100\%\approx8,5\%\\C\%_{HCl\left(dư\right)}=\dfrac{3,65}{111,7}\cdot100\%\approx3,27\%\end{matrix}\right.\)

\(a.Mg+2HCl->MgCl_2+H_2\\ b.n_{Mg}=\dfrac{2,4}{24}=0,1mol\\ n_{HCl}=\dfrac{109,5.10\%}{36,5}=0,3mol\\ n_{Mg}:1< n_{HCl}:2\\ Mg:hết\\ m_{ddsau}=2,4+109,5-2.0,1=111,7g\\ C\%_{HCl\left(dư\right)}=\dfrac{36,5.0,1}{111,7}.100\%=3,27\%\\ C\%_{MgCl_2}=\dfrac{95.0,1}{111,7}.100\%=8,50\%\)

Sửa đề : 109,5 ml $\to$ 109,5 gam

a) $Mg + 2HCl \to MgCl_2 + H_2$

b)

n Mg = 2,4/24 = 0,1(mol) ; n HCl = 109,5.10%/36,5  = 0,3(mol)

Ta thấy :

n Mg / 1 = 0,1 < n HCl /2 = 0,15 nên HCl dư

Theo PTHH :

n HCl pư = 2n Mg = 0,2(mol) => n HCl dư = 0,3- 0,2 = 0,1(mol)

n MgCl2 = n Mg = 0,1(mol)

Sau phản ứng : 

m dd = m Mg + m HCl - m H2 = 2,4 + 109,5 -0,1.2 =111,7(gam)

Vậy :

C% MgCl2 = 0,1.95/111,7  .100% = 8,5%

C% HCl = 0,1.36,5/111,7  .100%  = 3,27%

\(a)Mg+2HCl\rightarrow MgCl_2+H_2\)
\(b)n_{Mg}=\dfrac{3}{24}=0,125mol\\ n_{HCl}=0,1.1=0,1mol\\ \Rightarrow\dfrac{0,125}{1}>\dfrac{0,1}{2}\Rightarrow Mg.dư\\ n_{H_2}=n_{MgCl_2}=\dfrac{0,1}{2}=0,05mol\\ V_{H_2}=0,05.24,79=1,2395l\\ c)C_{M_{MgCl_2}}=\dfrac{0,05}{0,1}=0,5M\)

Chúc cậu học tốt nhee

a, \(Mg+2HCl\rightarrow MgCl_2+H_2\)

b, Ta có: \(n_{Mg}=\dfrac{2,4}{24}=0,1\left(mol\right)\)

Theo PT: \(n_{HCl}=2n_{Mg}=0,2\left(mol\right)\Rightarrow C\%_{HCl}=\dfrac{0,2.36,5}{400}.100\%=1,825\%\)

c, Theo PT: \(n_{MgCl_2}=n_{H_2}=n_{Mg}=0,1\left(mol\right)\)

Ta có: m _{dd sau pư} = 2,4 + 400 - 0,1.2 = 402,2 (g)

\(\Rightarrow C\%_{MgCl_2}=\dfrac{0,1.95}{402,2}.100\%\approx2,36\%\)

\(n_{Zn}=\dfrac{6.5}{65}=0.1\left(mol\right)\)

\(n_{H_2SO_4}=0.3\cdot1=0.3\left(mol\right)\)

\(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)

\(0.1........0.1...........0.1.......0.1\)

\(\Rightarrow H_2SO_4dư\)

\(n_{H_2SO_4\left(dư\right)}=0.3-0.1=0.2\left(mol\right)\)

\(n_{ZnSO_4}=n_{H_2}=0.1\left(mol\right)\)

\(C_{M_{ZnSO_4}}=\dfrac{0.1}{0.3}=0.33\left(M\right)\)

\(C_{M_{H_2SO_4\left(dư\right)}}=\dfrac{0.2}{0.3}=0.66\left(M\right)\)

\(a) Zn + H_2SO_4 \to ZnSO_4 + H_2\\ b) n_{Zn} = \dfrac{6,5}{65} = 0,1 < n_{H_2SO_4} =0,3 \to H_2SO_4\ dư\\ n_{H_2SO_4\ pư} = n_{ZnSO_4} = n_{Zn} = 0,1(mol)\\ n_{H_2SO_4\ dư} = 0,3 - 0,1 = 0,2(mol)\\ c) C_{M_{ZnSO_4}} = \dfrac{0,1}{0,3} = 0,33M\\ C_{M_{H_2SO_4}} = \dfrac{0,2}{0,3} = 0,67M\)

\(n_{Zn}=\dfrac{m}{M}=0,1\left(mol\right)\)

\(n_{H2SO4}=C_M.V=0,3\left(mol\right)\)

a, \(PTHH:Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)

b, Thấy 0,3 > 0,1

=> Sau phản ứng Zn hết, H2SO4 còn dư ( dư 0,3 - 0,1 = 0,2 mol )

- Theo PTHH : \(n_{ZnSO4}=n_{Zn}=0,1\left(mol\right)\)

c, Ta có : \(\left\{{}\begin{matrix}C_{MH2SO4}=\dfrac{n}{V}=\dfrac{2}{3}M\\C_{MZnSO4}=\dfrac{n}{V}=\dfrac{1}{3}M\end{matrix}\right.\)

Đặt : \(n_{CuO}=a\left(mol\right),n_{ZnO}=b\left(mol\right)\)

\(\Rightarrow80a+81b=28,25g\left(1\right)\)

a) Pt : \(CuO+2HCl\rightarrow CuCl_2+H_2O\)

\(ZnO+2HCl\rightarrow ZnCl_2+H_2O\)

b) Ta có : \(n_{HCl}=\dfrac{20\%.127,75}{100\%.36,5}=0,7\left(mol\right)\Rightarrow2a+2b=0.7\left(2\right)\)

Từ (1),(2) \(\Rightarrow\left\{{}\begin{matrix}a=0,1=n_{CuCl2}\\b=0,25=n_{ZnCl2}\end{matrix}\right.\)

c) \(m_{muối}=m_{CuCl2}+m_{ZnCl2}=0,1.135+0,25.136=47,5\left(g\right)\)

d) \(\left\{{}\begin{matrix}C\%_{CuCl2}=\dfrac{0,1.135}{28,25+127,75}.100\%=8,65\%\\C\%_{ZnCl2}=\dfrac{0,25.136}{28,25+127,75}.100\%=21,79\%\end{matrix}\right.\)

n Al=0,25 mol

2Al + 6HCl → 2AlCl₃ + 3H₂

0,25---0,75------0,25------0,375 mol

=>VH2=0,375.22,4=8,4l

=>m AlCl3=0,25.133,5=33,375g

=>CM HCl=\(\dfrac{0,75}{2}\)=0,375M