a,\(Mg+2HCl\rightarrow MgCl_2+H_2\)
Cu ko phản ứng với HCl
\(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
Theo PTHH: \(n_{Mg}=n_{H2}=0,2\left(mol\right)\)
\(\Rightarrow m_{Mg}=0,2\cdot24=4,8\left(g\right)\)
\(\Rightarrow m_{Cu}=8,8-4,8=4\left(g\right)\)\(\Rightarrow\%m_{Mg}=\dfrac{4,8}{8,8}\cdot100\%\approx54,54\%\Rightarrow\%m_{Cu}\approx100\%-54.54\%\approx45,46\%\)b, Theo PTHH:\(n_{HCl}=2\cdot n_{H2}=2\cdot0,2=0,4\left(mol\right)\)
\(\Rightarrow m_{HCl}=0,4\cdot36,5=14,6\left(g\right)\)
\(\Rightarrow m_{dd}_{HCl}=\dfrac{14,6}{5}\cdot100\%=292\left(g\right)\)