| − | In which W and C are the weights, in g, of the substance taken for the acetylation and for the free acid determination, respectively; N is the exact normality of the alcoholic potassium hydroxide; and 56.11 is the molecular weight of potassium hydroxide. [1] | + | In which W and C are the weights, in g, of the substance taken for the acetylation and for the free acid determination, respectively; N is the exact normality of the alcoholic potassium hydroxide; and 56.11 is the molecular weight of potassium hydroxide. <ref>Pharmacopedia/National Formulary. US. (2009) Vol. 1, p. 151</ref> |