nHCl = 1.2 =2mol
pt : Al2O3 + 6HCl ---------> 2AlCl3 + 3H2O
npứ:x------>6x
pt : Fe2O3 + 6HCl ------> 2FeCl3 + 3H2O
npứ:y-------->6y
ta có : \(\left\{{}\begin{matrix}102x+160y=34,2\\6x+6y=2\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{287}{870}\\y=\dfrac{1}{290}\end{matrix}\right.\)
mAl2O3=\(\dfrac{287}{870}.102\approx33,65g\)
mFe2O3=34,2 - 33,65=0,55g
%Fe2O3=\(\dfrac{0,55}{34,2}.10\approx1,61\%\)
%Al2O3 = \(\dfrac{33,65}{34,2}.100\approx98,39\%\)