CH3CO2H+\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{H}+CH3CO2H+\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{Na}$
NH4OH+NH4Cl\mathrm{NH}_{4} \mathrm{OH}+\mathrm{NH}_{4} \mathrm{Cl}NH4OH+NH4Cl
Na2CO3+NaHCO3\mathrm{Na}_{2} \mathrm{CO}_{3}+\mathrm{NaHCO}_{3}Na2CO3+NaHCO3
HClO4+NaClO4\mathrm{HClO}_{4}+\mathrm{NaClO}_{4}HClO4+NaClO4