Molar refraction, molar volume, and refractive index of fatty acid esters and related compounds in the liquid state

Summary Equations have been developed for the calculation of molar refraction, molar volume or density, and refractive index for liquid fatty acids and fatty acid derivatives in relation to two parameters, carbon chain length, and unsaturation. Particular attention has been given to the applicability of the equations to families of compounds in which the unsaturated members contain onlycis double bonds and in which the ethylene units of the polyene members are interrupted by methylene groups. The equations are sufficiently accurate to have considerable utility in establishing the identity, purity, or structure of various fatty acid derivatives. It was indicated that, with more data, similar relationships may be developed which will be useful in characterizing some types of mixtures of fatty acid derivatives. An approximate relationship between molar volume and temperature for fatty acids and derivatives was also devised.