\(m_{tăng}=m_M-m_{H_2}=6.6\left(g\right)\)
\(\Rightarrow m_{H_2}=7.2-6.6=0.6\left(g\right)\)
\(n_{H_2}=\dfrac{0.6}{2}=0.3\left(mol\right)\)
\(2M+2nHCl\rightarrow2MCl_n+nH_2\)
\(\dfrac{0.6}{n}.........................0.3\)
\(M_M=\dfrac{7.2}{\dfrac{0.6}{n}}=12n\)
\(\text{Biện luận : }\)
\(n=2\Leftrightarrow M=24\)
\(M\text{ là :Mg }\)