EXCESS MOLAR VOLUMES AND REFRACTIVE-INDEXES OF HEPTANOL PLUS PENTANE,PLUS HEXANE, PLUS HEPTANE, PLUS OCTANE, AND PLUS 2,2,4-TRIMETHYLPENTANE

Excess molar volumes, V-m(E), have been measured using a direct dilato metric technique for binary mixtures of heptanol (n-C7H15OH) + hexane (n-C6H14), + heptane (n-C7H16), + octane (n-C8H18), and + 2,2,4-trimet hylpentane (2,2,4-TMP) at 308.15 K and for n-C7H15OH + pentane (n-C5H1 2) at 298.15 K. The refractive indexes, n(D), have been measured for t hese mixtures at 303.15 K. V-m(E) has been found to be negative throug hout the entire range of composition for xn-C7H15OH + (1-x)n-C5H12 and xn-C7H15OH + (1-x)n-C6H14. V-m(E) has been found to be positive at lo wer values oft and negative at higher values of x for xn-C7H15OH + (1- x)2,2,4-TMP, xn-C7H15OH + (1-x)n-C7H16, and xn-C7H15OH + (1-x)n-C8H18, with the inversion of sign from positive to negative values of V-m(E) occurring at x similar to 0.06, x similar to 0.20, and x similar to 0 .45 respectively for these mixtures. Values of V-m(E) and n(D) for the various mixtures of n-C7H15OH have been fitted in smoothing equations .