\(\begin{array}{l}
Dat\,hoa\,tri\,A\,la\,n(n\in\mathbb{N^*})\\
2A+nCl_2\xrightarrow{t^o}2ACl_n\\
Theo\,PT:\,n_A=n_{ACl_n}\\
\to \dfrac{11,2}{M_A}=\dfrac{32,5}{M_A+35,5n}\\
\to M_A=\dfrac{56}{3}n\\
\to \begin{cases} n=3\\ M_A=56 \end{cases}\\
\to A:Fe
\end{array}\)