\(Đặt:nMg=a\left(mol\right),n_{MgCO_3}=b\left(mol\right)\)
\(n_{khí}=\dfrac{6.72}{22.4}=0.3\left(mol\right)\)
\(Mg+2HCl\rightarrow MgCl_2+H_2\)
\(a................a.......a\)
\(MgCO_3+2HCl\rightarrow MgCl_2+CO_2+H_2O\)
\(b....................b........b\)
\(m_X=24a+84b=13.2\left(g\right)\left(1\right)\)
\(n_{khí}=a+b=0.3\left(mol\right)\left(2\right)\)
\(\left(1\right),\left(2\right):a=0.2,b=0.1\)
\(m_{Mg}=0.2\cdot24=4.8\left(g\right),m_{MgCO_3}=0.1\cdot84=8.4\left(g\right)\)
\(m_{ddB}=13.2+200-0.2\cdot2-0.1\cdot44=208.4\left(g\right)\)
\(m_{MgCl_2}=0.3\cdot95=28.5\left(g\right)\)
\(C\%MgCl_2=\dfrac{28.5}{208.4}\cdot100\%=13.67\%\)
