Question

Which is more stable?

Short answer

a.

b.

c.

Step-by-step solution

Definition of secondary carbon and tertiary carbon.

A carbon atom that is bonded to two other carbon atoms is known as a secondary carbon.

Carbon atom that is bonded to three other carbon atoms is known as a tertiary carbon atom.

a. Tertiary carbon is more stable than secondary carbon 

The first one is more stable because tertiary carbon is more stable than secondary carbonbecause secondary and primary carbon free radicals are less stable than tertiary carbon free radicals because the radical is stabilised by the electrical effects of the other connected groups, resulting in hyperconjugation.

b. Which is more stable.

The first one is more stable because the electron withdrawing chlorine destabilizes the carbon by increasing the amount of positive charge on the carbon.

c. Which is more stable?

The second one is more stable because tertiary carbon is more stable than the secondary carbon.