How Do You Find The Acid Number?
Acid number is determined by titrating a sample of the substance with a standardized solution of alkali under specific conditions. The substance is dissolved in a suitable solvent and a small amount of phenolphthalein indicator is added. Titration is carried out with standardized sodium hydroxide solution (NaOH) using a burette. The acid number is calculated by the amount of alkali required to neutralize the free acids present in the substance.