\(n_{Na_2CO_3}=\dfrac{200.13,25%}{100\%.106}=0,25(mol)\\ n_{BaCl_2}=\dfrac{20,8\%.300}{100\%.208}=0,3(mol)\\ PTHH:Na_2CO_3+BaCl_2\to BaSO_4\downarrow +2NaCl\)
Vì \(\dfrac{n_{Na_2CO_3}}{1}<\dfrac{n_{BaCl_2}}{1}\) nên \(BaCl_2\) dư
Do đó dd sau p/ứ gồm \(BaCl_2\) dư và \(NaCl\)
\(n_{BaSO_4}=0,25(mol);n_{NaCl}=0,5(mol);n_{BaCl_2(dư)}=0,3-0,25=0,05(mol)\\ \Rightarrow m_{NaCl}=0,5.58,5=29,25(g);m_{BaCl_2(dư)}=0,05.208=10,4(g)\\ \Rightarrow C\%_{NaCl}=\dfrac{29,25}{200+300-0,25.233}.100\%=6,62\%\\ C\%_{BaCl_2(dư)}=\dfrac{10,4}{200+300-0,25.233}.100\%=2,35\%\)