Excess molar enthalpies, H(E), of binary mixtures of n-valeric anhydride or n-hexanoic anhydride with n-dodecane, n-tetradecane, or n-hexadecane were measured by an isothermal titration calorimeter at 298.15 K under atmospheric pressure. The experimental H(E) values are positive for all binary systems over the entire composition range. In these six investigated systems, the maximum values of H(E) exhibit at the composition ranging from 0.47 to 0.49 and 0.44 to 0.47 in the mole fraction of anhydrides for the mixtures containing n-valeric anhydride and n-hexanoic anhydride, respectively. The maximum values increase with increasinE chain length of the alkanes for the mixtures containing a given anhydride. A Redlich-Kister equation correlated the experimental H(E) data to within the experimental uncertainty. The new enthalpy data were also correlated, respectively, with the Peng-Robinson (PR), the Patel-Teja (PT), and two versions of the cubic chain-of-rotators (CCOR) equations of state and the NRTL model as well. The CCOR equation of state with two binary interaction parameters yielded the best representation for the investigated systems.