Câu 1$a)$
$2Al+6HCl\rightarrow 2AlCl_3+3H_2\uparrow$
$x 1,5x$
$Cu+2H_2SO_4\rightarrow CuSO_4+SO_2\uparrow+2H_2O$
$y y$
$2Ag+2H_2SO_4\rightarrow Ag_2SO_4+SO_2\uparrow+2H_2O$
$z 0,5z$
$\Rightarrow \begin{cases}27x+64y+108z=3,07 \\1,5x=\frac{336}{1000.22,4}\\y+0,5z=\frac{448}{1000.22,4} \end{cases}\Rightarrow \begin{cases}x=0,01 mol \\ y=0,01 mol\\z=0,02 mol \end{cases}\Rightarrow \begin{cases}m_{Al}=0,27 gam \\m_{Cu}=0,64 gam\\m_{Ag}=2,16 gam \end{cases}$
$b)$
$\begin{cases}n_{SO_2}=0,02 mol \\n_{KOH}=\frac{9,6.1,25.28}{100.56}=0,06 mol \end{cases} $
$2KOH+SO_2\rightarrow K_2SO_3+H_2O$
$\Rightarrow \begin{cases}n_{K_2SO_3}=0,02 mol \\n_{KOH}=0,02 mol\\m_{dd}=0,02.64+9,6.1,25=13,28 gam \end{cases}\Rightarrow \begin{cases}\%m_{K_2SO_3}=23,8\% \\\%m_{KOH}=8,43\% \end{cases}$