\(n_{Al_2O_3}=\dfrac{10.2}{102}=0.1\left(mol\right)\)
\(n_{HCl}=0.35\cdot2=0.7\left(mol\right)\)
\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)
\(1.................6\)
\(0.1.............0.7\)
Lập tỉ lệ : \(\dfrac{0.1}{1}< \dfrac{0.7}{6}\Rightarrow HCldư\)
\(m_{AlCl_3}=0.1\cdot2\cdot133.5=26.7\left(g\right)\)