Abstract Densities ρ of and speeds of sound u in binary mixtures cyclohexane + benzene and + benzaldehyde have been measured over the entire range of composition at atmospheric pressure and at temperatures ranging from (293.15 to 323.15) K using an Anton-Paar DSA 5000. From these data molar isentropic compressibilities KS,m, thermal expansion coefficients αP, excess molar volumes V m E , and excess molar isentropic compressibilities K S , m E at all the temperatures, and excess thermal expansion coefficients α P E and isothermal pressure coefficient of excess molar enthalpy ( ∂ H m E / ∂ P ) T , x at 298.15 K were calculated. The V m E for both the mixtures are positive at all temperatures and over entire range of compositions. The K S , m E are positive over entire composition for cyclohexane + benzene while K S , m E curve is S-shaped for cyclohexane + benzaldehyde. The values of α P E are negative except for cyclohexane rich region in both the mixtures. The values of all the excess functions are lower for cyclohexane + benzaldehyde as compared to cyclohexane + benzene at all the temperatures and compositions.