Gọi `x = n_(Al) ` ; `y = n_(Mg)`
`n_(H_2) = 4.368 / 22.4 = 0.195 ( mol ) `
a) `PTHH : `
`2Al + 6HCl -> 2AlCl_3 + 3 H_2`
` Mg + 2HCl -> MgCl_2 + H_2`
Theo đề ra , ta có hệ phương trình :
$\begin{cases}27x + 24y = 3.87\\3/2x+y = 0.195\end{cases}$ $⇔$ $ \begin{cases}x = 0.09\\y = 0.06\end{cases}$
`%m_(Al) = {0.09 × 27} / 3.87 = 62.79 %`
`%m_(Mg) = 100% - 62.79% = 37.21%`
b)
`BTNT ( H ) : n_(HClpứ) = 2n_(H_2) = 2 × 0.195 = 0.39 ( mol ) `
`Cm_(HCldư) = n / V = 0.11 / 0.5 = 0.22 ( M ) `
`Cm_(AlCl_3) = n / V = 0.09 / 0.5 = 0.18 ( M ) `
`Cm_(ZnCl_) = n / V = 0.06 / 0.5 = 0.12 ( M ) `