\(n_{CuO}=\dfrac{3,2}{80}=0,04\left(mol\right)\)

\(n_{H_2SO_4}=\dfrac{100.20\%}{98}=0,204\left(mol\right)\)

PTHH:

\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)

0,04      0,04           0,04    

\(\dfrac{0,04}{1}< \dfrac{0,204}{1}\) --> H2SO4 dư

\(C\%_{CuSO_4}=\dfrac{0,04.160}{3,2+100}.100\%=6,2\%\)

\(C\%_{H_2SO_4\left(dư\right)}=\dfrac{0,2.98}{3,2+100}.100\%=19\%\)

\(n_{Fe}=\dfrac{2.8}{56}=0.2\left(mol\right)\)

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

\(0.2......0.4..........0.2\)

\(V_{dd_{HCl}}=\dfrac{0.4}{1}=0.4\left(l\right)\)

\(C_{M_{HCl}}=\dfrac{0.2}{0.4}=0.5\left(M\right)\)

a)

$n_{Al}  = \dfrac{5,4}{27} = 0,2(mol)$

$2Al + 3H_2SO_4 \to Al_2(SO_4)_3 + 3H_2$
Theo PTHH: 

$n_{H_2SO_4} = n_{H_2} = \dfrac{3}{2}n_{Al} = 0,3(mol)$
$V_{dd\ H_2SO_4} = \dfrac{0,3}{2} = 0,15(lít)$
$n_{Al_2(SO_4)_3} = \dfrac{1}{2}n_{Al} = 0,1(mol)$
$C_{M_{Al_2(SO_4)_3}} = \dfrac{0,1}{0,15} = 0,67M$

b)

$V_{H_2} = 0,3.22,4 = 6,72(lít)$

PTHH: \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\uparrow\)

            \(Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\)

a+b) Ta có: \(n_{Zn}=\dfrac{19,5}{65}=0,3\left(mol\right)=n_{H_2SO_4}=n_{ZnSO_4}\) 

\(\Rightarrow C_{M_{H_2SO_4}}=\dfrac{0,3}{0,2}=1,5\left(M\right)=C_{M_{ZnSO_4}}\)

c) Theo PTHH: \(n_{H_2}=n_{Zn}=0,3mol\) \(\Rightarrow V_{H_2}=0,3\cdot22,4=6,72\left(l\right)\)

d) Theo PTHH: \(n_{Fe}=\dfrac{2}{3}n_{H_2}=0,2mol\)

\(\Rightarrow m_{Fe}=0,2\cdot56=11,2\left(g\right)\)

a, \(Fe+CuSO_4\rightarrow FeSO_4+Cu\)

b, \(n_{Fe}=\dfrac{1,96}{56}=0,035\left(mol\right)\)

\(m_{ddCuSO_4}=100.1,12=112\left(g\right)\)

\(\Rightarrow n_{CuSO_4}=\dfrac{112.10\%}{160}=0,07\left(mol\right)\)

Xét tỉ lệ: \(\dfrac{0,035}{1}< \dfrac{0,07}{1}\), ta được CuSO₄ dư.

Theo PT: \(n_{CuSO_4\left(pư\right)}=n_{FeSO_4}=n_{Cu}=n_{Fe}=0,035\left(mol\right)\)

\(\Rightarrow n_{CuSO_4\left(dư\right)}=0,07-0,035=0,035\left(mol\right)\)

Ta có: m _{dd sau pư} = 1,96 + 112 - 0,035.64 = 111,72 (g)

\(\Rightarrow\left\{{}\begin{matrix}C\%_{FeSO_4}=\dfrac{0,035.152}{111,72}.100\%\approx4,76\%\\C\%_{CuSO_4}=\dfrac{0,035.160}{111,72}.100\%\approx5,01\%\end{matrix}\right.\)