Mg2+ + SO42- + Ba2+ + 2OH- = BaSO4+Mg(OH)2CaCO3+2HAc=CaAc2+CO2+H2O
MgSO4+Ba(OH)2=BaSO4↓+Mg(OH)2↓CaCO3+2CH3COOH=(CH3COO)2Ca+CO2↑
(Ba+)+(Mg+)+2(OHˉ）+(SO4+)=Mg(OH)2↓+BaSO4↓
