The acidity function H_ of diethyl amine (DEA) and triethyl amine (TEA
) in aqueous solutions, ethanolic solutions and ethanol-water mixtures
has been determined spectrophotometrically, using as indicator butana
l 2,4-dinitrophenylhydrazone. The function H_ lies within the range fr
om 12.5 to 14.2. The basicity of solutions increases with the water co
ntent, and the order of basicity of the amines is TEA < DEA.