$*)\begin{cases}Na:x mol \\ Al:y mol\\Fe:z mol \end{cases}$$TN_1\Rightarrow n_{H_2}=0,5x+1,5x=2x mol$
$TN_2\Rightarrow n_{H_2}=(0,5x+1,5y) mol$
$TN_3\Rightarrow n_{H_2}=(0,5x+1,5y+z) mol$
$\Rightarrow 2x:(0,5x+1,5y):(0,5x+1,5y+z)=1:\frac{11}{8}:\frac{19}{8}=8:11:19$
Chọn $x=4 mol\Rightarrow y=6\Rightarrow z=8 mol\Rightarrow x:y:z=2:3:4$
$\Rightarrow \begin{cases}\%Na=\frac{23x}{23x+27y+56z}.100=\frac{23.2}{23.2+27.3+56.4}.100=13,11\% \\ \%Al=23,08\% \\\%Fe=63,81\%\end{cases}$