\(n_{AlCl_.}=\dfrac{5.34}{133.5}=0.04\left(mol\right)\)
\(2Al+6HCl\rightarrow2AlCl_3+3H_2\)
\(0.04......................0.04\)
\(m_{Al}=\dfrac{0.04\cdot27}{90\%}=1.2\left(g\right)\)
\(n_{AlCl_3}=\dfrac{5,34}{133,5}=0,04(mol)\\ PTHH:2Al+6HCl\to 2AlCl_3+3H_2\\ \Rightarrow n_{Al(phản ứng)}=0,04(mol)\\ \Rightarrow n_{Al(cần dùng)}=\dfrac{0,04.27}{90\%}=1,2(g)\)