a)
$Zn + S \xrightarrow{t^o} ZnS$
$n_{Zn} =\dfrac{9,75}{65} = 0,15 > n_S = \dfrac{3,84}{32} = 0,12$ nên Zn dư
$n_{ZnS} = n_S = 0,12(mol)$
$m_{ZnS} = 0,12.97 = 11,64(gam)$
$n_{Zn\ dư} = 0,15 - 0,12 = 0,03(mol)$
$m_{Zn\ dư} = 0,03.65 = 1,95(gam)$
b)
$Zn + 2HCl \to ZnCl_2 + H_2$
$ZnS + 2HCl \to ZnCl_2 + H_2S$
$n_{khí} = n_{H_2} + n_{H_2S} = n_{Zn\ dư} + n_{ZnS} = 0,15(mol)$
$V = 0,15.22,4 = 3,36(lít)$
\(n_{Zn}=\dfrac{9.75}{65}=0.15\left(mol\right)\)
\(n_S=\dfrac{3.84}{32}=0.12\left(mol\right)\)
\(Zn+S\underrightarrow{^{^{t^0}}}ZnS\)
Lập tỉ lệ :
\(\dfrac{0.15}{1}>\dfrac{0.12}{1}\Rightarrow Zndư\)
\(a.\)
\(m_X=m_{ZnS}+m_{Zn\left(dư\right)}=0.12\cdot97+\left(0.15-0.12\right)\cdot65=13.59\left(g\right)\)
\(b.\)
\(Zn+2HCl\rightarrow ZnCl_2+H_2\)
\(0.03..................................0.03\)
\(ZnS+2HCl\rightarrow ZnCl_2+H_2S\)
\(0.12.................................0.12\)
\(V_{khí}=0.03\cdot22.4+0.12\cdot22.4=3.36\left(l\right)\)