2HCl+CaCO3=CaCl2+H2O+CO2 酸+碱—→盐+水H2SO4+Cu(OH)2=CuSO4+2H20 盐+盐—→两种新盐Na2SO4+BaCl2=2NaCl+BaSO4↓ 盐+碱—→新盐+新碱 2NaOH+CuSO4=Na2SO4+Cu(OH)2↓ 1、酸+碱:HCl+NaOH=NaCl+H2O 2、酸+盐:2HCl+Na2CO3=2NaCl+H2O+CO2
产物要有水或气体或沉淀
