 Therefore, 2-methylhexane has a lower Autoignition temperature and flash point when compared to heptane.Theoretically 2-methylhexane also burns with a less sooty flame, emitting higher-frequency radiation; however, as heptane and 2-methylhexane differ by only one carbon atom, in terms of branching, both burn with a bright yellow flame when ignited.Compared to n-heptane, 2-methylhexane also has lower melting and boiling points.