a) \(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\)

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

           0,4-->0,6---------->0,2------->0,6

=> \(C_{M\left(dd.H_2SO_4\right)}=\dfrac{0,6}{0,15}=4M\)

b) V_H2 = 0,6.22,4 = 13,44 (l)

c) \(C_{M\left(Al_2\left(SO_4\right)_3\right)}=\dfrac{0,2}{0,15}=\dfrac{4}{3}M\)

\(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\\ pthh:2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\) 
           0,4     0,6                   0,2             0,6 
\(C_M_{H_2SO_4}=\dfrac{0,6}{0,15}=4M\\ V_{H_2}=0,622,4=13,44L\) 
\(C_M=\dfrac{0,2}{0,15}=1,3M\)

a. \(n_{SO_3}=\dfrac{8}{80}=0,1\left(mol\right)\)

\(C_M=\dfrac{0,1}{200}=0,0005\left(mol\text{/}l\right)\) 

\(1,n_{Mg}=\dfrac{7,2}{24}=0,3\left(mol\right)\)

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

           0,3---->0,6------------------>0,3

\(2,C_{M\left(HCl\right)}=\dfrac{0,6}{0,3}=2M\\ 3,V_{H_2}=0,3.22,4=6,72\left(l\right)\)

\(n_{Fe}=\dfrac{11,2}{56}=0,2mol\)

\(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)

0,2     0,2                0,2       0,2

a)\(V_{H_2}=0,2\cdot22,4=4,48l\)

b)\(C_{M_{H_2SO_4}}=\dfrac{0,2}{0,5}=0,4M\)

c)\(C_{M_{FeSO_4}}=\dfrac{0,2}{0,5}=0,4M\)

\(n_{Fe}=\dfrac{11,2}{56}=0,2\left(mol\right)\) 
pthh : \(Fe+H_2SO_4->FeSO_4+H_2\) 
          0,2                                      0,2
=> \(V_{H_2}=0,2.22,4=4,48\left(L\right)\) 
\(m_{H_2SO_4}=\dfrac{0,5}{22,4}.98\approx2,188\left(g\right)\) 
=> mdd=11,2+2,188=13,388(g) 
C%=\(\dfrac{2,188}{13,388}.100\%=16,3\%\)

\(n_K=\dfrac{39}{39}=1\left(mol\right)\\ 2K+2H_2O\rightarrow2KOH+H_2\\ n_{H_2}=\dfrac{1}{2}=0,5\left(mol\right)\\ a,V_{H_2\left(đktc\right)}=0,5.22,4=11,2\left(l\right)\\ b,n_{KOH}=n_K=1\left(mol\right)\\ C_{MddKOH}=\dfrac{1}{0,2}=5\left(M\right)\\ c,2H_2+O_2\rightarrow\left(t^o\right)2H_2O\\ n_{O_2}=\dfrac{0,5}{2}=0,25\left(mol\right)\\ V_{O_2\left(đktc\right)}=0,25.22,4=5,6\left(l\right)\)

a, \(2Na+2H_2O\rightarrow2NaOH+H_2\)

b, \(n_{Na}=\dfrac{4,6}{23}=0,2\left(mol\right)\)

Theo PT: \(n_{NaOH}=n_{Na}=0,2\left(mol\right)\Rightarrow m_{NaOH}=0,2.40=8\left(g\right)\)

c, \(C_{M_{NaOH}}=\dfrac{0,2}{0,2}=1\left(M\right)\)

a) \(n_{Fe}=\dfrac{2,8}{56}=0,05\left(mol\right)\)

PTHH: `Fe + 2HCl -> FeCl_2 + H_2`

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

`=> V_{ddHCl} = (0,1)/2 = 0,05 (l)`

b) `V_{H_2} = 0,05.22,4 = 1,12 (l)`

c) `C_{M(FeCl_2)} = (0,05)/(0,05) = 1M`