In figure , the composition obtained using our calculation is denoted by the solid line and the dashed, dashed dotted and dotted lines represent the equilibrium mole fractions obtained using the heats of formation and their lower and upper bounds respectively, given by Gingerich et al. Looking at the mole fractions, differences primarily lie in the mole fractions of C 4 and C 6 molecules. is observed that the C 4 equilibrium mole fraction at lower temperature is higher than that of C 3 .