SPEEDS OF SOUND IN AND ISENTROPIC COMPRESSIBILITIES OF (N-BUTANOL PLUS N-PENTANE) AT T = 298.15 K, AND (N-BUTANOL PLUS N-HEXANE, OR N-HEPTANE, OR N-OCTANE, OR 2,2,4-TRIMETHYLPENTANE) AT T = 303.15 K

Measurements of speeds of sound u have been made in binary mixtures of n-butanol (n-C4H9OH) with n-pentane (n-C5H12) at T = 298.15 K, and in the mixtures of n-C4H9OH with n-hexane (n-C6H14), or n-heptane (n-C7H 16), or n-octane (n-C8H18), or 2,2,4-trimethyl pentane {2,2,4-(CH3)(3) C5H9} at T = 303.15 K. Values of u have been used to calculate the app arent excess speeds of sound hu and the isentropic compressibilities k appa(S) for these mixtures. The excess isentropic compressibilities ka ppa(S)(E) have also been calculated from the values of kappa(S). The k appa(S)(E) values have been found to be highly negative for {xn-C4H9OH + (1 - x)n-C4H12}. The values of kappa(S)(E) have been found to be po sitive at lower mole fractions of n-C4H9OH and negative at its higher mole fractions for {xn-C4H9OH + (1 - x)n-C6H14}, {xn-C4H9OH + (1 - x)n -C6H14}, {xn-C4H9OH + (1 - x)n-C6H14}, and {xn-C4H9OH + (1 - x)2,2,4-( CH3)(3)C5H9}. The inversion of sign in kappa(S)(E) occurs at x approxi mate to 0.11, x approximate to 0.60, x approximate to 0.89, and x appr oximate to 0.26, respectively, for these mixtures. The Delta u and kap pa(S)(E) have been fitted with smoothing equations. (C) 1998 Academic Press.