\(n_{Al}=\dfrac{5.4}{27}=0.2\left(mol\right)\)
\(2Al+6HCl\rightarrow2AlCl_3+3H_2\)
\(0.2........0.6.........................0.3\)
\(m_{HCl}=0.6\cdot36.5=21.9\left(g\right)\)
\(V_{H_2}=0.3\cdot22.4=6.72\left(l\right)\)
a) $2Al + 6HCl \to 2AlCl_3 + 3H_2$
b) n Al = 5,4/27 = 0,2(mol)
n HCl = 3n Al = 0,6(mol)
=> m HCl = 0,6.36,5 = 21,9 gam
c) n H2 = 3/2 n Al = 0,3(mol)
=> V H2 = 0,3.22,4 = 6,72 lít