91Ó°ÊÓ

The addition of water to a molecule is called hydration reaction, so we can say that an alkene is hydratedin the presence of water and acid as only water is not a good electrophile to do addition reaction with alkene.

That reaction will be hydrated rapidly which forms a stable carbocation in the transition state. The stability of carbocation depends on the hyperconjugation and the degree of carbocation formed.

The series of carbocation according to their stability is,

3°&²µ³Ù;2°&²µ³Ù;1°.

To understand about the rapidity in the hydration reaction, we need to see the reaction mechanism 1^st.

For the 1^st alkene

For the 2^nd alkene:

Now as the carbocation transition state is more stable for the 1^st compound, the hydration reaction will be faster for the 1^st alkene.