MOLAR EXCESS VOLUMES OF BINARY-LIQUID MIXTURES - 2-PYRROLIDINONE WITHC-6-C-10 N-ALKANOLS

The excess volumes V-E Of the binary mixtures 2-pyrrolidinone - (C-6-C -10) n-alkanols have been calculated from density measurements over th e whole composition range and the 298.15-318.15 K temperature range. T he excess volumes were independent of temperature, but changed noticea bly with the chain length of the alkanol. The V-E values were only pos itive starting from heptanol, with the maximum value, 0.239 cm(3) mol( -1), for equimolar decanol. The observed changeover V-E <0 to V-E >0 s uggests that the steric effect is primarily responsible for the positi ve contributions to V-E. The thermal expansion coefficients alpha were evaluated from the variation af densities with temperature.