Acidity is frequently expressed as the Acid Value, which is the number of mg of potassium hydroxide required to neutralize the free acids in 1.0 g of the substance<ref>Warth, A. H.; The Chemistry and Technology of Waxes. Reinhold Publishing Corporation. Second Edition, p. 586</ref>

Acidity is frequently expressed as the Acid Value, which is the number of mg of potassium hydroxide required to neutralize the free acids in 1.0 g of the substance<ref>Warth, A. H.; The Chemistry and Technology of Waxes. Reinhold Publishing Corporation. Second Edition, p. 586</ref>.

The acid value of a wax is determined by dissolving a known amount of the wax in alcohol and titrating the solution against standard alkali solution.

The acid value of a wax is determined by dissolving a known amount of the wax in alcohol and titrating the solution against standard alkali solution.

==USP 401==

==USP 401==

The acidity of fats and fixed oils in USP may be expressed as the number of mL of  0.1 N alkali required to neutralize the free acids in 10.0 g of substance.

The acidity of fats and fixed oils in USP may be expressed as the number of mL of  0.1 N alkali required to neutralize the free acids in 10.0 g of substance<ref>Pharmacopedia/National Formulary. US., Vol. 1, 2009, p. 150</ref>.