Glycolic acid is an organic compound with the chemical formula C2H4O3. It is a colorless crystal that is easily deliquescent. Soluble in water, soluble in methanol, ethanol, ethyl acetate and other organic solvents, slightly soluble in ether, insoluble in hydrocarbons. It has dual properties of alcohol and acid, and decomposes when heated to the boiling point. Used in organic synthesis, etc.