Measurements of density, viscosity, and refractive index in the T = (283.15 to 353.15) K temperature range at atmospheric pressure and vapor pressure over the P = (1.0 to 96.7, or 96.0, or 95.2, or 50) kPa pressure range for alpha-pinene, d-limonene, (+/-)-linalool, and citral, respectively, were made. The temperature dependence of these properties was fitted to empirical relations. The molar enthalpy of vaporization for these chemicals was calculated plotting the logarithm of the vapor pressure against the reciprocal temperature and using the Clausius-Clapeyron equation. The enantiomer ratios of alpha-pinene, d-limonene, and (+/-)-linalool were also obtained.