Câu 1) Oxit kim loại là $M_2O_n $
$M_2O_n +2nHCl \to 2MCl_n+nH_2O$
$→ 11,1.(2M+16n)=5,6.2(M+35,5n)$
$→ M=20n=40$
$→$ Công thức kim loại là $Ca$
Câu 2) $2KMnO_4 + 16HCl \to 2KCl + 2MnCl_2 + 5Cl_2 + 8H_2O$
$n_{Cl_2}=\dfrac52 n_{KMnO_4}=0,225\ (mol)$
$→V_{Cl_2}=0,225.22,4=5,04\ (l)$
Câu 3) $Fe + 2HCl \to FeC{l_2} + {H_2}\\0,1\quad\;\; 0,2\qquad\qquad\quad\;\;\; 0,1$
$FeO + 2HCl \to FeC{l_2} + {H_2}O\\0,1\qquad\; 0,2$
$n_{H_2}=n_{Fe}=\dfrac{2,24}{22,4}=0,1\ (mol)$
$n_{FeO}=\dfrac{12,8-0,1.56}{72}=0,1\ (mol)$
$\sum n_{HCl}=2n_{FeO}+2n_{Fe}=0,1.2+0,1.2=0,4\ (mol)$
$→V_{HCl}=\dfrac{0,4}{0,1}=4\ (l)$