Comparing the half-life data with the experimental heats of formation at 298 K (∆H f ), a frequently used stability surrogate, illustrates the qualitative error of neglecting kinetics in assessing stability. A larger exothermic ∆H f corresponds to higher thermodynamic stability, and a lower half-life corresponds to lower kinetic stability. The thermodynamic data compiled by Pedley, Naylor, and Klein (PNK data) shows that thermodynamic stability increases with alkane length while kinetic stability decreases (Fig. ). The thermodynamic trend also misses the half-life discontinuity between n-butane and n-pentane. Comparing ∆H f and the half-life of linear (n-alkanes)