Question

When does carbocation rearrangement occur?

Answer 1

carbocation can be formed from a primary carbocationbecause a secondary carbocation is more stable than the primary carbocation. There can be two types of rearrangements.

Answer 2

Carbocation rearrangement occurs because of hydride ,phenyl,methyl shift...with aptitude of hydride shift being the most. It usually occurs when there is a possibility of a more stable carbocation like tertiary or allylic carbocation ,etc.

Hope it helps