Zn + 2HCl → ZnCl2 + H2↑
\(n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
\(\Rightarrow m_{H_2}=0,15\times2=0,3\left(g\right)\)
a) Theo PT: \(n_{Zn}=n_{H_2}=0,15\left(mol\right)\)
\(\Rightarrow m_{Zn}=0,15\times65=9,75\left(g\right)\)
\(\Rightarrow m_{Cu}=12-9,75=2,25\left(g\right)\)
\(\Rightarrow\%Zn=\dfrac{9,75}{12}\times100\%=81,25\%\)
\(\%Cu=\dfrac{2,25}{12}\times100\%=18,75\%\)
b) Theo PT: \(n_{HCl}=2n_{H_2}=2\times0,15=0,3\left(mol\right)\)
\(\Rightarrow m_{HCl}=0,3\times36,5=10,95\left(g\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{10,95}{8\%}=136,875\left(g\right)\)
c) Theo PT: \(n_{ZnCl_2}=n_{H_2}=0,15\left(mol\right)\)
\(\Rightarrow m_{ZnCl_2}=0,15\times136=20,4\left(g\right)\)
\(m_{dd}saupư=12+136,875-0,3=148,575\left(g\right)\)
\(\Rightarrow C\%_{ZnCl_2}=\dfrac{20,4}{148,575}\times100\%=13,73\%\)
