Vapor—liquid phase equilibria for the isoprene—n-pentane binary system from 300 to 330 K

This article presents new, total pressure data for the isoprene—n-pentane binary system over the temperature range 300–330 K. The experimental design procedure of Howat and Swift was used as a guide for the selection of data points and for the analysis of the impact of random and potential systematic errors on the data. Regression analysis procedures used are those presented by Shanker et al. Quatitative data are presented which show the effect of mercury—hydrocarbon interaction on the measured vapor pressures of C5 hydrocarbons. The new data surpass the precision of any previously published literature data for this binary pair. The uncertainty in the measurements are 0.02 K, 0.08 kPa and 0.002 mole fraction. The predicted azeotrope composition is 0.743±0.003 mole fraction isoprene with no significant change with temperature.