Densities and refractive indices of normal acids from acetic acid to octanoic acid were measured in the temperature range 20-50 °C. Densities and refractive indices of oleic acid were also measured at the same temperature range. The Eykman equation was used to check the accuracy of experimental densities and refractive indices. The refractive indices obtained by using the Lorentz-Lorenz equation agree with experimental ones within an average deviation of about ±0.0005.

Densities and refractive Indices of -plnene, /3-plnene, (S)-(-)-limonene, and p-cymene were measured In the temperature range 20-50 °C.