The unimolecular solvolysis of 2-bromo-2-methylpropane in pure aqueous conditions yields a highly st — Haloalkanes and Haloarenes Chemistry Question
Question
The unimolecular solvolysis of 2-bromo-2-methylpropane in pure aqueous conditions yields a highly stable mixture of *tert*-butyl alcohol and 2-methylpropene. Which of the following advanced statements rigorously define the intricate kinetic relationship between the $S_N1$ and $E1$ mechanisms operating simultaneously in this specific reaction flask?
💡 Solution & Explanation
A) True. The tertiary halide heterolytically ionizes to form the highly stable *tert*-butyl cation. Water can then either act as a nucleophile to attack the positive carbon ($S_N1$) or act as a base to abstract a proton from a peripheral methyl group ($E1$). Both strictly utilize the same intermediate. B) False. The rate of disappearance of the alkyl halide is strictly and entirely determined by the *slow* ionization step ($Rate = k_1[RX]$). It is fundamentally independent of the fast subsequent steps. C) False. Adding a strong base to the mixture would immediately physically change the entire mechanism from unimolecular ($S_N1/E1$) to bimolecular ($E2$), completely altering the rate law and bypassing the carbocation formation entirely. D) True. Once the shared carbocation intermediate is fully formed, it partitions rapidly into products based solely on the kinetic competition (the relative activation energies) between the subsequent nucleophilic attack and proton abstraction steps.