\(n_{HCl}=0.3\cdot1=0.3\left(mol\right)\)
\(R_2O_n+2nHCl\rightarrow2RCl_n+nH_2O\)
\(\dfrac{0.15}{n}.......0.3\)
\(M=\dfrac{8}{\dfrac{0.15}{n}}=\dfrac{160}{3}n\)
\(\Rightarrow2R=+16n=\dfrac{160}{3}n\)
\(\Leftrightarrow R=\dfrac{56}{3}n\)
\(n=3\Rightarrow R=56\)
\(R:Fe\)
