C2H5OH\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}C2H5OH
CH3CO2C2H5\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{C}_{2} \mathrm{H}_{5}CH3CO2C2H5
CH3COOH\mathrm{CH}_{3} \mathrm{COOH}CH3COOH
CH3COONa\mathrm{CH}_{3} \mathrm{COONa}CH3COONa