The excess molar volume, excess speed of sound, excess isentropic compressibility, excess thermal expansion, and excess refractive index (RI) were determined from measurements of density, speed of sound, and RI for the systems of n-heptane (1) + pentan-2-one (2)/4-methylpentan-2-one (2) in the temperature range of 298.15-338.15 K and at an atmospheric pressure of 0.101 MPa. The density, speed of sound, and RIs of the mixtures were nonlinear and decreased with increasing temperature. The excess volume was found to increase with temperature, with the maxima at approximately x(1) = 0.6 mole fraction. Relevant excess properties were fitted using 5-parameter Redlich -Kister expansions and were mostly correlated within experimental uncertainty.