Chemical potential for model benzene fluid at liquid densities is calculated using the expanded ensemble method, modified to permit continuous sampling in lambda-space. The density is varied from 0.2 g/cm(3) to 0.9 g/cm(3). Three different temperatures (T = 300 K, 400 K, and 600 K) are considered to provide data below and above the critical temperature (T-c = 5562.16 K). Two different potential models, the Evans-Watts model and the Claessens＇ model, are considered, both of which are rigid hexagonal models with six sites interacting by a Lennard-Jones potential. Despite its simplicity, we found that the results obtained using Claessens＇ model are in very good agreement with experimental data.