Why is the boiling point of 2,2-Dimethyl propanol greater than 3-Pentanol ?

Dear student,
As the surface area of 2,2-Dimethyl propanol is less then pentan-3-ol(116⁰C), the molecules are closer together , hence apart from H-bonding which is same for both molecules, Vanderwaals forces also come into action , due to vicinity of electrons of oter shell in molecules.
Hence more branched chain requires more energy to overcome this additional Van der wal’s force, hence has higher boilin point(aprx 206⁰C)