\(4.a/n_{Al}=\dfrac{5,4}{27}=0,2mol\\ 2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

0,2       0,3                  0,1                  0,3

\(V_{H_2}=0,3.24,79=7,437l\\ b/C_{\%H_2SO_4}=\dfrac{0,3.98}{150}\cdot100=19,6\%\\ c/m_{Al_2\left(SO_4\right)_3}=0,1.342=34,2g\)

\(5.a/n_{MgO}=\dfrac{4}{40}=0,1mol\\ MgO+2HCl\rightarrow MgCl_2+H_2O\)

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

\(C_{\%HCl}=\dfrac{0,2.36,5}{200}\cdot100=3,65\%\\ b/C_{\%MgCl_2}=\dfrac{0,1.95}{200+4}\cdot100=4,66\%\\ c/NaOH+HCl\rightarrow NaCl+H_2O\\ n_{NaOH}=n_{HCl}=0,2mol\\ V_{NaOH}=\dfrac{0,2}{1}=0,2l=200ml\)

\(a)n_{CuO}=\dfrac{8}{80}=0,1mol\\ CuO+2HCl\rightarrow CuCl_2+H_2O\\ n_{CuCl_2}=n_{Cu}=0,1mol\\ m_{CuCl_2}=0,1.135=13,5g\\ b)n_{HCl}=0,1.2=0,2mol\\ C_{M_{HCl}}=\dfrac{0,2}{0,2}=1M\\ c)C_{M_{CuCl_2}}=\dfrac{0,1}{0,2}=0,5M\)

a) Mg + 2HCl -> MgCl2 + H2
Al + 3HCl -> AlCl3 + 3/2H2

b) Gọi a, b lần lượt là số mol Mg, Al.

nH2 = 5,6/22,4 = 0,25 (mol)

Mg + 2HCl -> MgCl2 + H2

a        2a            a          a
Al + 3HCl -> AlCl3 + 3/2H2

b           3b       b          3/2b

Ta có hệ pt: 

mhh = 24a + 27b = 5,1 (g)

nH2 = a + 3/2b = 0,25 (mol)

=> a = 0,1 (mol)

b = 0,1 (mol)

200 ml = 0,2 l

nHCl = 2a + 3b = 0,2 + 0,3 = 0,5 (mol)

=> CM ddHCl = 0,5/0,2 = 2,5 (M)

%mMg = 24a/5,1*100% = 2,4/5,1*100% = 47,06%

%mAl = 100%-47,06% = 52,94%

\(a.BTNT\left(H\right):n_{HCl}=2n_{H_2}=0,65\left(mol\right)\\ \Rightarrow CM_{HCl}=\dfrac{0,65}{0,5}=1,3M\\ b.2Al+6HCl\rightarrow2AlCl_3+3H_2\\ Fe+2HCl\rightarrow FeCl_2+H_2\\ Đặt:\left\{{}\begin{matrix}n_{Al}=x\left(mol\right)\\n_{Fe}=y\left(mol\right)\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}\dfrac{3}{2}x+y=0,325\\27x+56y=9,65\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}x=0,15\\y=0,1\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}m_{Al}=4,05\left(g\right)\\m_{Fe}=5,6\left(g\right)\end{matrix}\right.\)

\(4.\\ a/n_{Al}=\dfrac{5,4}{27}=0,2mol\\2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

\(0,2......0,3............0,1...............0,3\)

\(V_{H_2}=0,3.24,79=7,437l\\ b.C_{\%H_2SO_4}=\dfrac{0,3.98}{150}\cdot100=19,6\%\\ c.m_{Al_2\left(SO_4\right)_3}=0,1.342=34,2g\)

\(7.\\a) n_{H_2SO_4}=\dfrac{100.9,8}{100.98}=0,1mol\\ ZnO+H_2SO_4\rightarrow ZnSO_4+H_2O\\ n_{ZnO}=n_{ZnSO_4}=n_{H_2SO_4}=0,1mol\\ m_{ZnO}=0,1.81=8,1g\\ b)C_{\%ZnSO_4}=\dfrac{0,1.161}{8,1+100}\cdot100=14,8\%\)

\(9.\\ a)n_{H_2}=\dfrac{2,479}{24,79}=0,1mol\\ Mg+2HCl\rightarrow MgCl_2+H_2\)

\(0,1.....0,2.........0,1........0,1\)

\(m_{Mg}=0,1.24=2,4g\\ m_{MgO}=8,4-2,4=6g\\ b)n_{MgO}=\dfrac{6}{40}=0,15mol\\ MgO+2HCl\rightarrow MgCl_2+H_2O\\ n_{HCl}=0,15.2+0,2=0,5mol\\ m_{ddHCl}=\dfrac{0,5.36,5}{3,65}\cdot100=500g\)

\(n_{HCl}=0,3.2=0,6\left(mol\right)\\a, 2Al+6HCl\rightarrow2AlCl_3+3H_2\\ b,n_{H_2}=\dfrac{3}{6}.0,6=0,3\left(mol\right)\\ V_{H_2\left(đktc\right)}=0,3.22,4=6,72\left(l\right)\\ c,n_{Al}=n_{AlCl_3}=\dfrac{2}{6}.0,6=0,2\left(mol\right)\\ m_{Al}=0,2.27=5,4\left(g\right)\\ d,V_{ddAlCl_3}=V_{ddHCl}=0,3\left(l\right)\\ C_{MddHCl}=\dfrac{0,2}{0,3}=\dfrac{2}{3}\left(M\right)\)

a.\(n_{Mg}=\dfrac{4,8}{24}=0,2mol\)

\(Mg+2HCl\rightarrow MgCl_2+H_2\)

0,2                                     0,2      ( mol )

\(V_{H_2}=0,2.24,79=4,958l\)

b.\(n_{Na}=\dfrac{6,9}{23}=0,3mol\)

\(2Na+2H_2O\rightarrow2NaOH+H_2\)

0,3                                         0,15   ( mol )

\(V_{H_2}=0,15.24,79=3,7185l\)

c.\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

  0,05                                              0,075      ( mol )

\(V_{H_2}=0,075.24,79=1,85925l\)

a, Ta có: 27n_Al + 56n_Fe = 22 (1)

PT: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

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

Theo PT: \(n_{H_2}=\dfrac{3}{2}n_{Al}+n_{Fe}=\dfrac{19,832}{24,79}=0,8\left(mol\right)\left(2\right)\)

Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}m_{Al}=0,4\left(mol\right)\\n_{Fe}=0,2\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}\%m_{Al}=\dfrac{0,4.27}{22}.100\%\approx49,09\%\\\%m_{Fe}\approx50,91\%\end{matrix}\right.\)

b, \(n_{HCl}=2n_{H_2}=1,6\left(mol\right)\)

\(\Rightarrow C_{M_{HCl}}=\dfrac{1,6}{0,5}=3,2\left(M\right)\)