A. BaCO3+2HCl=BaCl2+CO2↑+H2O,CO32-+2H+=CO2↑+H2O B. 2NaOH+H2SO4=Na2SO4+2H2O,H++OH-=H2O C. Cu+2AgNO3=2Ag+Cu(NO3)2,Cu+Ag+=Cu2++Ag D. H2SO4+Ba(OH)2 =BaSO4↓+2H2O, H++OH-+Ba2++SO42- =BaSO4↓+H2O
A. Mg2++2OH-=Mg(OH)2↓,MgSO4+Ba(OH)2 =Mg(OH)2↓+BaSO4↓ B. Fe+Cu2+=Fe2++Cu,Fe+Cu(OH)2 =Fe(OH)2 +Cu C. Ag++Cl-=AgCl↓ ,AgNO3+HCl =AgCl↓+HNO3 D. CO2+2OH-=CO32-+H2O,CO2+Ca(OH)2 =CaCO3↓+H2O