PTHH: \(BaCl_2+H_2SO_4\rightarrow BaSO_4+2HCl\)
a) Ta có: \(n_{BaCl_2}=\frac{20,8}{208}=0,1\left(mol\right)\) \(\Rightarrow n_{H_2SO_4}=0,1mol\)
\(\Rightarrow m_{H_2SO_4}=98\cdot0,1=9,8\left(g\right)\) \(\Rightarrow m_{ddH_2SO_4}=\frac{9,8}{9,8\%}=100\left(g\right)\)
b) Theo PTHH: \(n_{BaCl_2}=n_{BaSO_4}=0,1mol\)
\(\Rightarrow m_{BaSO_4}=0,1\cdot233=23,3\left(g\right)\)
c) Theo PTHH: \(n_{BaCl_2}:n_{HCl}=1:2\) \(\Rightarrow n_{HCl}=0,2mol\)
\(\Rightarrow m_{HCl}=0,2\cdot36,5=7,3\left(g\right)\)
Ta có: \(m_{dd}=m_{BaCl_2}+m_{ddH_2SO_4}-m_{BaSO_4}=20,8+100-23,3=97,5\left(g\right)\) \(\Rightarrow C\%_{HCl}=\frac{7,3}{97,5}\cdot100\approx7,49\%\)