Ta có: \(m_{tăng}=m_{KL}-m_{H_2}\) \(\Rightarrow m_{H_2}=0,8\left(g\right)\) \(\Rightarrow n_{H_2}=\dfrac{0,8}{2}=0,4\left(mol\right)\)
PTHH: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)
a_____________________\(\dfrac{3}{2}\)a (mol)
\(Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\)
b____________________b (mol)
Ta lập HPT: \(\left\{{}\begin{matrix}27a+24b=7,8\\\dfrac{3}{2}a+b=0,4\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=0,2\\b=0,1\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{Mg}=0,1\cdot24=2,4\left(g\right)\\m_{Al}=5,4\left(g\right)\end{matrix}\right.\)
