a,\(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
PTHH: 2Al + 6HCl → 2AlCl3 + 3H2
Mol: x 1,5x
PTHH: Fe + 2HCl → FeCl2 + H2
Mol: y y
Ta có: \(\left\{{}\begin{matrix}27x+56y=5,5\\1,5x+y=0,2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0,1\\y=0,05\end{matrix}\right.\)
\(\Rightarrow\%m_{Al}=\dfrac{0,1.27.100\%}{5,5}=49,09\%;\%m_{Fe}=100-49,09=50,91\%\%\)
b,
PTHH: 2Al + 6HCl → 2AlCl3 + 3H2
Mol: 0,1 0,3
PTHH: Fe + 2HCl → FeCl2 + H2
Mol: 0,05 0,1
\(n_{HCl}=0,3+0,1=0,4\left(mol\right)\Rightarrow C_{M_{ddHCl}}=\dfrac{0,4}{0,5}=0,8M\)
c,\(n_{AlCl_3}=n_{Al}=0,1\left(mol\right);n_{FeCl_2}=n_{Fe}=0,05\left(mol\right)\)
PTHH: 3NaOH + AlCl3 → 3NaCl + Al(OH)3
Mol: 0,1 0,1
PTHH: 2NaOH + FeCl2 → 2NaCl + Fe(OH)2
Mol: 0,05 0,05
⇒ mkết tủa = 0,1.78+0,05.90 = 12,3 (g)