Final answer:
A tertiary carbocation forms rather than a secondary carbocation because it is more stable due to inductive effects from adjacent alkyl groups and lesser steric hindrance, allowing for more favorable chemical reactions such as substitutions and eliminations.
Step-by-step explanation:
A tertiary carbocation is formed rather than a secondary carbocation because it is more stable. This stability comes from the inductive effect where the positively charged carbon atom (carbocation) is stabilized by the adjacent alkyl groups (R groups) through electron donation. Additionally, the planar nature of the carbocation allows for attack by nucleophiles from either side, leading to a mixture of enantiomers in chiral products. In biochemical reactions, like enzyme activity, the active site's chiral nature directs the reaction to produce only one enantiomer. In chemical reactions, tertiary alkyl halides and allylic phosphates often undergo substitution reactions favoring the formation of the more stable tertiary carbocation over the secondary one.
Considering oxidation and elimination reactions, tertiary alcohols cannot be oxidized to ketones or aldehydes because there's no hydrogen atom attached to the carbon bearing the hydroxyl group. However, they can undergo elimination reactions more readily through E2 mechanisms due to less steric hindrance. With less steric crowding, the tertiary carbocation forms more easily, facilitating the reaction process as opposed to primary and secondary substrates, where sterics and mechanism preference (SN2 vs E2) lead to different outcomes.