Fe2O3 + 6HCl → 2FeCl3 + 3H2O (1)
CuO + 2HCl → CuCl2 + H2O (2)
a) \(m_{CuO}=20\times20\%=4\left(g\right)\)
\(\Rightarrow m_{Fe_2O_3}=20-4=16\left(g\right)\)
b) \(n_{CuO}=\dfrac{4}{80}=0,05\left(mol\right)\)
\(n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\)
Theo PT1: \(n_{HCl}=6n_{Fe_2O_3}=6\times0,1=0,6\left(mol\right)\)
Theo PT2: \(n_{HCl}=2n_{CuO}=2\times0,05=0,1\left(mol\right)\)
\(\Rightarrow\Sigma n_{HCl}=0,1+0,6=0,7\left(mol\right)\)
\(\Rightarrow m_{HCl}=0,7\times36,5=25,55\left(g\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{25,55}{5,475\%}=466,67\left(g\right)\)
c) Dung dịch sau phản ứng gồm: CuCl2 và FeCl3
Theo PT1: \(n_{FeCl_3}=2n_{Fe_2O_3}=2\times0,1=0,2\left(mol\right)\)
\(\Rightarrow m_{FeCl_3}=0,2\times162,5=32,5\left(g\right)\)
Theo PT2: \(n_{CuCl_2}=n_{CuO}=0,05\left(mol\right)\)
\(\Rightarrow m_{CuCl_2}=0,05\times135=6,75\left(g\right)\)
\(\Sigma m_{dd}=20+466,67=486,67\left(g\right)\)
\(\Rightarrow C\%_{FeCl_3}=\dfrac{32,5}{486,67}\times100\%=6,68\%\)
\(C\%_{CuCl_2}=\dfrac{6,75}{486,67}\times100\%=1,39\%\)