\(n_{H_2}=\dfrac{m}{M}=\dfrac{1}{2}=0,5\left(mol\right)\)
\(pthh:\overset{Mg}{x}\overset{+2HCl\overset{t^o}{\rightarrow}}{\overset{ }{\overset{ }{ }}}\overset{MgCl_2}{x}\overset{+H_2}{x}\left(1\right)\\ \overset{Fe}{y}\overset{+2HCl\overset{t^o}{\rightarrow}}{\overset{ }{\overset{ }{ }}}\overset{FeCl_2}{x}\overset{+H_2}{y}\left(2\right)\)
Từ \(\left(1\right)\) và \(\left(2\right)\), ta có hệ pt:
\(\left\{{}\begin{matrix}x+y=0,5\\24x+56y=20\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,25\\y=0,25\end{matrix}\right.\)
\(\Rightarrow n_{MgCl_2}=x=0,25\left(mol\right)\\ \Rightarrow m_{MgCl_2}=n\cdot M=0,25\cdot95=23,75\left(g\right)\\ \Rightarrow n_{FeCl_2}=y=0,25\left(mol\right)\\ \Rightarrow m_{FeCl_2}=n\cdot M=0,25\cdot127=31,75\left(g\right)\\ \Rightarrow m_{h^2\left(MgCl_2+FeCl_2\right)}=23,75+31,75=55,5\left(g\right)\)
