Nitrogen (N-2) is widely used in oil and gas industry. We report two new efficient closed-form representations for the molar entropy and Gibbs free energy of pure gaseous substances. A comparison of the predicted and experimental values shows that the molar entropies and Gibbs free energies of N-2 can be excellently predicted in the temperature range of 100-6000 K. The present entropy and Gibbs free energy prediction models only require the experimental values of three molecular constants and are away from the utilization of a great number of experimental spectroscopy data. (C) 2019 Elsevier Ltd. All rights reserved.