Although there is no quantitative relationship between the stability of a high-energy carbocation intermediate and the rate of its formation, there is an intuitive relationship. It’s generally true when comparing two similar reactions that the more stable intermediate forms faster than the less stable one. The situation is shown graphically in Figure 6.15, where the reaction energy profile in part (a) represents the typical situation. The profile in part (b) is atypical-that is, the curves for two similar reactions don’t cross one another: