Apparent molar volumes V-phi and apparent molar heat capacities C-p,C-phi were determined for aqueous solutions of sodium bromide NaBr(aq) at molalities m = (0.01 to 1.0) mol (.) kg(-1) and of aqueous sodium fluoride NaF(aq) at molalities m = (0.01 to 0.7) mol (.) kg(-1) at temperatures T = (278.15 to 393.15) K and at the pressure 0.35 MPa. Our V-phi values were calculated from densities obtained using a vibrating-tube densimeter, and our C-p,C-phi values were obtained using a twin fixed-cell, power-compensation, differential-output, temperature-scanning calorimeter. Our results were fitted to functions of m and T, and estimated values of V-phi and C-p,C-phi of the anions F-(aq), Cl-(aq), and Br-(aq) are compared over the ranges of m and T given above. (C) 2004 Elsevier Ltd. All rights reserved.