a)
$Fe + S \xrightarrow{t^o} FeS$
$FeS + 2HCl \to FeCl_2 + H_2S$
$Fe + 2HCl \to FeCl_2 + H_2$
$CuSO_4 + H_2S \to CuS + H_2SO_4$
$A : FeS,S,Fe$
$B : FeCl_2$
$D : H_2S,H_2$
$E : S$
b)
Theo PTHH :
$n_{H_2S} = n_{CuS} = \dfrac{19,2}{96} = 0,2(mol)$
$\Rightarrow n_{Fe\ dư} = n_{H_2} = n_D - n_{H_2S} = 0,1(mol)$
$m_{S\ dư} = m_E = 3,2(gam)$
Theo PTHH :
$n_{Fe\ pư} = n_{S\ pư} = n_{FeS} = n_{H_2S} = 0,2(mol)$
Suy ra :
$m_{Fe\ ban\ đầu} = 0,2.56 + 0,1.56 = 16,8(gam)$
$m_{S\ ban\ đầu} = 0,2.32 + 3,2 = 9,6(gam)$
A: FeS
B: FeCl2
D: H2S; H2
E: S
\(Fe+S\rightarrow\left(t^o\right)FeS\) (1)
\(FeS+2HCl\rightarrow FeCl_2+H_2S\uparrow\) (2)
\(Fe+2HCl\rightarrow FeCl_2+H_2\) (3)
\(H_2S+CuSO_4\rightarrow CuS\downarrow+H_2SO_4\) (4)
\(n_{hhk}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\) (5)
\(n_{CuS}=\dfrac{19,2}{96}=0,2\left(mol\right)\)
\(\left(4\right);\left(5\right)\rightarrow\left\{{}\begin{matrix}n_{H_2S}=0,2\\n_{H_2}=0,1\end{matrix}\right.\) ( mol )
\(n_S=n_{CuS}=0,2\left(mol\right)\)
\(\rightarrow m_S=3,2+0,2.32=9,6\left(g\right)\)
\(\left(2\right);\left(4\right)\rightarrow n_{Fe}=n_S=0,2\left(mol\right)\)
\(\left(3\right)\rightarrow n_{H_2}=n_{Fe}=0,1\left(mol\right)\)
\(m_{Fe}=0,3.56=16,8\left(g\right)\)
