\(m_{HX}=\dfrac{10,95.200}{100}=21,9\left(g\right)\)
\(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)
PTHH: 2Al + 6HX --> 2AlX3 + 3H2
0,2--->0,6-------------->0,3
=> \(M_{HX}=\dfrac{21,9}{0,6}=36,5\left(g/mol\right)\)
=> X là Cl
VH2 = 0,3.22,4 = 6,72(l)