Final answer:
Tertiary leaving groups are more likely to undergo SN1 reactions due to their stability and steric hindrance. The stability of the leaving group allows for easier detachment and formation of carbocation intermediates, while steric hindrance prevents SN2 reactions.
Step-by-step explanation:
Tertiary leaving groups are more likely to undergo SN1 reactions than SN2 reactions due to several factors. Firstly, in SN1 reactions, the leaving group detaches from the substrate to form a carbocation intermediate before the nucleophile attacks. Tertiary leaving groups are more stable than primary and secondary leaving groups, making them easier to detach and form carbocation intermediates.
Secondly, the steric hindrance around the carbon atom in tertiary substrates prevents the nucleophile from approaching the carbon atom and undergoing an SN2 reaction. The nucleophile is hindered by the surrounding substituents, reducing the likelihood of an SN2 reaction.
Overall, the combination of the stability of tertiary leaving groups and the steric hindrance around the carbon atom make SN1 reactions more favorable for tertiary substrates.