vd4.
a, \(n_{H_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)
PTHH: Fe + 2HCl → FeCl2 + H2
Mol: 0,3 0,6 0,3 0,3
\(m_{Fe}=0,3.56=16,8\left(g\right)\)
b, \(V_{ddHCl}=\dfrac{0,6}{2}=0,3\left(l\right)\)
c, \(m_{FeCl_2}=0,3.127=38,1\left(g\right)\)
vd5.
\(n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
PTHH: Mg + H2SO4 loãng → MgSO4 + H2
Mol: 0,15 0,15
\(\%m_{Mg}=\dfrac{0,15.24.100\%}{7}=51,43\%\)
\(\%m_{Fe}=100-51,43=48,57\%\)