Experimental isothermal (P,x,y) data for the ternary system (2-butanol+ 2,2,4-trirnethylpentane + 1-hexene) and for the binary system (2-butanol + 1-hexene) at 313.15 K are reported. Data reduction using Barker's method provides correlations for G(E), using the Margules equation for the binary system and the Wohl expansion for the ternary system. Wilson, NRTL, and UNIQUAC models have also been applied successfully to both of the binary and ternary mixtures presented here. (c) 2014 Elsevier B.V. All rights reserved.