Ta có:
\(\left\{{}\begin{matrix}n_{Cl2}=\frac{4,48}{22,4}=0,2\left(mol\right)\\n_{H2}=\frac{2,24}{22,4}=0,1\left(mol\right)\end{matrix}\right.\)
\(R+Cl_2\rightarrow MCl_2\)
0,2__0,2______
\(M+2HCl\rightarrow MCl_2+H_2\)
0,1__________________0,1
\(n_M=0,2+0,1=0,3\left(mol\right)\)
\(\Rightarrow M_M=\frac{7,2}{0,3}=24\)
Vậy kim loại M là Magie (Mg)