Câu 5:

$a,PTHH:Zn+2HCl\to ZnCl_2+H_2(1)$

$ZnO+2HCl\to ZnCl_2+H_2O(2)$

$b,$ Theo $PT(1):n_{Zn}=n_{H_2}=\dfrac{2,24}{22,4}=0,1(mol)$

$\Rightarrow m_{Zn}=0,1.65=6,5(g)$

$\Rightarrow m_{ZnO}=m_{hh}-m_{Zn}=12-6,5=5,5(g)$

$c,n_{ZnO}=\dfrac{5,5}{81}=\dfrac{11}{162}(mol)$

Theo $PT(1)(2)\Rightarrow \Sigma n_{HCl}=2n_{Zn}+2n_{ZnO}\approx 0,336(mol)$

$\Rightarrow m_{HCl}=0,336.36,5=12,264(g)$

$\Rightarrow C\%_{HCl}=\dfrac{12,264}{100}.100\%=12,264\%$

Câu 6:

$a,PTHH:Fe+H_2SO_4\to FeSO_4+H_2$

Theo PT: $n_{Fe}=n_{H_2}=\dfrac{0,896}{22,4}=0,04(mol)$

$\Rightarrow m_{Fe}=0,04.56=2,24(g)$

$\Rightarrow m_{Cu}=8-2,24=5,76(g)$

$b,PTHH:Cu+2AgNO_3\to Cu(NO_3)_2+2Ag\downarrow$

$\Rightarrow n_{Cu}=\dfrac{5,76}{64}=0,09(mol)$

Theo PT: $n_{AgNO_3}=2n_{Cu}=0,18(mol)$

$\Rightarrow m_{AgNO_3}=0,18.170=30,6(g)$