Data are provided and estimation methods presented for the calculation of specific heat capacities, viscosities, thermal conductivities and diffusion coefficients for both pure components and mixtures Of C3H8, C2H6, CH4, H2O, CO2, CO2, H-2, N-2. O-2 and Ar over the temperature range 273-1473 K at ambient pressure. Pure component data is assembled from various data compilations supplemented by validated estimation techniques. Fourteen estimation methods for mixture properties have been compared with each other and with over 1400 experimental data points to facilitate the choice of methods best suited to this application. A statistical analysis of the data (including expected accuracy) is presented and recommendations are made for practical use.